# CalcFit - Complete Reference

Free online fitness calculators: TDEE, BMR, macro, calorie deficit, body fat, protein intake, BMI, ideal weight, one-rep max, and daily water intake. Science-backed formulas, instant results.

Last updated: 2026-08-18T06:42:16.401Z

## TDEE Calculator
Calculate your Total Daily Energy Expenditure -- the number of calories your body burns per day including exercise.
- URL: https://fit.thicket.sh/tdee
- Inputs: age, sex (male/female), height (cm or ft/in), weight (kg or lbs), activity level (sedentary, lightly active, moderately active, very active, extremely active)
- Outputs: TDEE in calories/day, BMR, calorie targets for weight loss (-500), moderate loss (-250), maintenance, and weight gain (+500)
- Formulas: Mifflin-St Jeor (primary), Harris-Benedict (secondary). Activity multipliers: sedentary 1.2, light 1.375, moderate 1.55, very active 1.725, extreme 1.9
- Method: BMR = 10 * weight(kg) + 6.25 * height(cm) - 5 * age - 161 (female) or + 5 (male). TDEE = BMR * activity multiplier.

## BMR Calculator
Calculate your Basal Metabolic Rate -- calories burned at complete rest.
- URL: https://fit.thicket.sh/bmr
- Inputs: age, sex, height, weight, formula preference
- Outputs: BMR in calories/day using Mifflin-St Jeor equation
- Formula: Men: 10 * weight(kg) + 6.25 * height(cm) - 5 * age + 5. Women: 10 * weight(kg) + 6.25 * height(cm) - 5 * age - 161.

## Macro Calculator
Calculate daily macronutrient targets (protein, carbs, fat) based on your TDEE and fitness goal.
- URL: https://fit.thicket.sh/macros
- Inputs: TDEE or manual calorie target, goal (lose fat, maintain, build muscle), diet preference (balanced, high-protein, low-carb, keto)
- Outputs: grams and calories for protein, carbohydrates, and fat. Percentage breakdown.
- Method: Protein set first (0.8-1.2g per lb bodyweight depending on goal), fat at 25-35% of calories, remainder to carbs.

## Calorie Deficit/Surplus Calculator
Plan calorie intake for weight loss or muscle gain with projected timelines.
- URL: https://fit.thicket.sh/calories
- Inputs: current weight, goal weight, TDEE, target deficit/surplus (or rate of change per week)
- Outputs: daily calorie target, weekly deficit/surplus, estimated time to reach goal weight
- Method: 1 lb fat = ~3,500 calories. Daily deficit of 500 cal = ~1 lb/week loss.

## Body Fat Calculator
Estimate body fat percentage using circumference measurements.
- URL: https://fit.thicket.sh/body-fat
- Inputs: sex, height, waist circumference, neck circumference, hip circumference (women only)
- Outputs: body fat percentage, fat mass, lean mass, body fat category (essential, athletes, fitness, average, obese)
- Formula: U.S. Navy method. Men: 86.010 * log10(waist - neck) - 70.041 * log10(height) + 36.76. Women: 163.205 * log10(waist + hip - neck) - 97.684 * log10(height) - 78.387.

## Protein Calculator
Calculate optimal daily protein intake based on weight and fitness goals.
- URL: https://fit.thicket.sh/protein
- Inputs: weight, activity level, goal (maintain, lose fat, build muscle)
- Outputs: protein grams/day (range), protein per meal (assuming 3-5 meals)
- Method: Sedentary 0.8g/kg, active 1.2-1.6g/kg, muscle building 1.6-2.2g/kg.

## BMI Calculator
Calculate Body Mass Index with WHO classification.
- URL: https://fit.thicket.sh/bmi
- Inputs: height, weight
- Outputs: BMI value, WHO category (underweight <18.5, normal 18.5-24.9, overweight 25-29.9, obese class I 30-34.9, class II 35-39.9, class III 40+)
- Formula: BMI = weight(kg) / height(m)^2

## Ideal Weight Calculator
Find ideal body weight using multiple clinical formulas.
- URL: https://fit.thicket.sh/ideal-weight
- Inputs: sex, height
- Outputs: ideal weight from four formulas -- Devine, Robinson, Miller, Hamwi -- plus an average
- Formulas (men, height in inches over 5 feet): Devine: 50 + 2.3 * (height - 60). Robinson: 52 + 1.9 * (height - 60). Miller: 56.2 + 1.41 * (height - 60). Hamwi: 48 + 2.7 * (height - 60).

## One Rep Max Calculator
Estimate your one-rep maximum for strength training.
- URL: https://fit.thicket.sh/one-rep-max
- Inputs: weight lifted, number of reps completed (2-12 recommended)
- Outputs: estimated 1RM, percentage chart (95% through 50% of 1RM for 2-15 reps)
- Formulas: Epley: weight * (1 + reps/30). Brzycki: weight * 36 / (37 - reps). Lombardi: weight * reps^0.10.

## Water Intake Calculator
Calculate daily water needs based on body weight, activity, and climate.
- URL: https://fit.thicket.sh/water-intake
- Inputs: weight, activity level, climate (temperate, hot, cold), exercise duration
- Outputs: daily water intake in liters and oz, glasses per day
- Method: Base 30-35 mL per kg body weight, plus exercise and climate adjustments.

## Pace Calculator
Calculate running pace, time, or distance for training and race planning.
- URL: https://fit.thicket.sh/pace-calculator
- Inputs: any two of: distance, time, pace. Plus unit preference (miles/km).
- Outputs: the missing variable, plus split times for common race distances (5K, 10K, half marathon, marathon)

## Calories Burned Calculator
Estimate calories burned during various physical activities.
- URL: https://fit.thicket.sh/calories-burned
- Inputs: activity type, duration, body weight
- Outputs: calories burned, MET value used
- Method: Calories = MET * weight(kg) * duration(hours). Uses Compendium of Physical Activities MET values.

## Heart Rate Zones Calculator
Calculate training heart rate zones for cardio optimization.
- URL: https://fit.thicket.sh/heart-rate-zones
- Inputs: age, resting heart rate (optional)
- Outputs: five heart rate zones (zone 1: 50-60%, zone 2: 60-70%, zone 3: 70-80%, zone 4: 80-90%, zone 5: 90-100% of max HR)
- Formulas: Max HR = 220 - age. Karvonen method with resting HR: target = ((max - resting) * intensity) + resting.

## Max Heart Rate Calculator
Calculate maximum heart rate using multiple age-based formulas.
- URL: https://fit.thicket.sh/max-heart-rate
- Inputs: age
- Outputs: max heart rate using Fox (220-age), Tanaka (208 - 0.7*age), Gulati (206 - 0.88*age for women)

## Lean Body Mass Calculator
Estimate lean body mass (everything except fat).
- URL: https://fit.thicket.sh/lean-body-mass
- Inputs: sex, weight, height
- Outputs: lean body mass in kg/lbs, body fat mass
- Formulas: Boer: men 0.407W + 0.267H - 19.2, women 0.252W + 0.473H - 48.3. James formula also provided.

## Waist-to-Hip Ratio Calculator
Assess health risk via waist and hip measurements.
- URL: https://fit.thicket.sh/waist-hip-ratio
- Inputs: waist circumference, hip circumference, sex
- Outputs: ratio value, WHO risk category (low, moderate, high)
- Method: WHR = waist / hip. High risk: men >0.90, women >0.85.

## Body Recomp Calculator
Plan simultaneous fat loss and muscle gain.
- URL: https://fit.thicket.sh/body-recomp
- Inputs: weight, body fat %, activity level, training experience
- Outputs: calorie cycling plan (training vs rest days), macro targets for each day type

## Body Type Quiz
Identify your somatotype (ectomorph, mesomorph, endomorph).
- URL: https://fit.thicket.sh/body-type
- Inputs: series of body measurement and characteristic questions
- Outputs: primary and secondary body type classification with training and nutrition recommendations

## Muscle Gain Calculator
Estimate realistic muscle gain potential over time.
- URL: https://fit.thicket.sh/muscle-gain
- Inputs: sex, body weight, training experience (years), body fat %
- Outputs: monthly and yearly muscle gain potential in lbs/kg, calorie surplus recommendation
- Method: Based on Alan Aragon and Lyle McDonald models. Beginners 1-1.5% bodyweight/month, intermediate 0.5-1%, advanced 0.25-0.5%.

## Daily Steps Calculator
Calculate calorie burn from daily step count.
- URL: https://fit.thicket.sh/daily-steps
- Inputs: step count, body weight, stride length (optional)
- Outputs: distance walked, calories burned, active minutes estimate
- Method: ~0.04 calories per step per kg bodyweight. Distance = steps * stride length.

## Featured Articles (2026-04-20 batch 3 — 30-article threshold)
- Can You Target Belly Fat?: https://fit.thicket.sh/blog/can-you-target-belly-fat
  Direct answer: No — you cannot spot-reduce belly fat (or fat anywhere). "Spot reduction" is a myth. In a controlled trial, 6 weeks of abdominal exercise (7 moves, 5 days/week) produced no reduction in belly fat vs a no-ab-training control (Vispute 2011, J Strength Cond Res, PMID 21804427). Single-limb designs confirm it: one-legged endurance resistance training and upper-body training caused systemic, not regional, fat loss (Ramirez-Campillo 2013, PMID 23222084; Kostek 2007, MSSE, PMID 17596787). Fat leaves the body in a pattern set by genetics, hormones, receptor density, and regional blood flow — the abdomen (especially in men) is often first stored and last lost, so it needs a larger overall body-fat drop to change visibly. Crunches build the abdominal muscle underneath but burn negligible calories and remove no overlying fat. What works: a sustained calorie deficit lowers total body fat, taking abdominal fat with it. Deeper visceral fat is especially responsive to aerobic exercise even without scale weight loss (Vissers 2012 meta-analysis, Obes Rev, PMID 21951360). Plan: find maintenance (TDEE), set ~500 kcal/day deficit, keep protein high to protect muscle, add regular cardio; expect the waistline to lag the scale by weeks.
- How Many Rest Days Per Week Do You Need?: https://fit.thicket.sh/blog/how-many-rest-days-per-week
  Direct answer: Most people need 1-3 rest days per week; the deciding factor is recovery, not a fixed number. A hard-trained muscle needs ~48 hours to rebuild — muscle protein synthesis stays elevated ~24-48h after a heavy resistance session (MacDougall 1995, Can J Appl Physiol, PMID 8563679), which is why full-body routines leave a day between sessions and splits give each muscle several days off. By level: beginner 3-4 training / 3-4 rest; intermediate (full-body or upper/lower) 4-5 / 2-3; advanced (body-part split) 5-6 / 1-2; returning after a break 3 / 4. When weekly volume is equated, training a muscle 2x/week matches or slightly beats 1x (Schoenfeld 2016 frequency meta-analysis, Sports Med, PMID 27102172), so spread work across more days to build in recovery. Active recovery (easy walk, light cycling, mobility, Zone 2) keeps you moving without hard stress and is not a rest day if it leaves you tired. Distinct from a deload week (planned volume reduction every several weeks). Signs you need more rest: stalled/declining performance, persistent fatigue, mood disturbance, disrupted sleep, low motivation, elevated morning resting HR (Meeusen 2013 ECSS/ACSM overtraining consensus, MSSE, PMID 23247672). Muscle is built during rest, not during the workout — treat recovery as part of the program.
- What Is a Good Resting Heart Rate?: https://fit.thicket.sh/blog/what-is-a-good-resting-heart-rate
  Direct answer: 60-100 bpm is the normal adult range (American Heart Association); lower within it generally means a fitter heart, and well-trained endurance athletes often sit at 40-60 bpm because a stronger heart pumps more blood per beat. By-fitness-level bands: well-trained athlete 40-54, excellent 55-61, good 62-68, average 69-75, below average 76-81, elevated 82+. Measure first thing in the morning before caffeine — two fingers on wrist or neck, count 30 sec x2, average several days; wearables log overnight lows. A higher resting rate tracks higher risk: each 10 bpm increase associated with higher CVD and all-cause mortality (Aune 2017 dose-response meta-analysis, Nutr Metab Cardiovasc Dis, PMID 28552551; Zhang 2016 general-population meta-analysis, CMAJ, PMID 26598376). Resting HR is modifiable — aerobic training lowers it over weeks to months. Temporary raisers: caffeine, stress, dehydration, poor sleep, alcohol, illness/fever, heat, some meds (beta-blockers lower it). Distinct from max heart rate. See a clinician if consistently >100 bpm or <60 bpm with dizziness/fainting.
- How Much Water Should You Drink a Day?: https://fit.thicket.sh/blog/how-much-water-should-you-drink-a-day
  Direct answer: adequate total water intake is ~3.7 L (125 oz)/day for men and ~2.7 L (91 oz)/day for women (U.S. National Academies, 2004). "Total" includes water from food, which supplies ~20%, so the amount to actually drink is ~3.0 L / 13 cups (men) and ~2.2 L / 9 cups (women). The "8 glasses a day" (8x8) rule — ~1.9 L of fluid — has no firm scientific basis (Valtin 2002, American Journal of Physiology, PMID 12376390) and under-counts larger/active people. Food contributes ~20% (watermelon, cucumber, lettuce, oranges are >85% water). Coffee and tea count (mild diuretic effect doesn't cause net dehydration at normal intakes); alcohol doesn't. Guides: thirst and pale straw-colored urine. Needs rise with exercise (+0.4-0.8 L/hour), heat, altitude, fever, pregnancy (~3.0 L), breastfeeding (~3.8 L). Overhydration causes hyponatremia (dilutes blood sodium) — kidneys clear ~0.8-1.0 L/hour, so space fluids; use electrolytes for long sweaty sessions. Includes recommended-intake-by-group table.
- How Many Calories Should I Eat to Lose Weight?: https://fit.thicket.sh/blog/how-many-calories-to-lose-weight
  Direct answer: eat ~500 kcal/day below your TDEE for ~1 lb/week of fat loss. Two steps — estimate TDEE (Mifflin-St Jeor), then subtract the deficit. A 200-lb person maintaining at ~2,600 kcal targets ~2,100 kcal/day. Safe rate 0.5-1% bodyweight/week (CDC: 1-2 lb/week). The 3,500-kcal-per-pound rule overpredicts long-term loss because a smaller body burns fewer calories — Hall 2011 dynamic model (The Lancet, PMID 21872751); NIH Body Weight Planner (niddk.nih.gov/bwp) gives personalized targets. Adaptive thermogenesis (~100-300 kcal/day) plus mass loss shrink the deficit over time; recompute TDEE every 10-15 lb. Do not go below ~1,200 kcal (women) / ~1,500 kcal (men) without supervision. Includes calorie-target-by-bodyweight table.
- What Is a Healthy Waist-to-Height Ratio?: https://fit.thicket.sh/blog/waist-to-height-ratio-healthy-range
  Direct answer: below 0.5 — keep your waist under half your height. WHtR = waist ÷ height (same units). Zones: <0.40 possible underweight, 0.40-0.49 healthy, 0.50-0.59 increased risk, 0.60+ high risk; same thresholds for men and women. Measure waist at the midpoint of the lowest rib and top of hip bone at normal exhale. NICE 2022 obesity guidance endorses the "waist less than half your height" message; Ashwell, Gunn & Gibson 2012 meta-analysis of 300,000+ adults (PMID 22106927) found WHtR predicts diabetes, hypertension, and CVD better than BMI. Captures visceral fat that BMI misses. Lower it via overall fat loss (no spot reduction); visceral fat mobilizes early in a deficit. Includes max-healthy-waist-by-height table.
- How Much Protein Do I Need to Build Muscle?: https://fit.thicket.sh/blog/how-much-protein-to-build-muscle
  Direct answer: 1.6-2.2 g/kg/day (0.7-1.0 g/lb). Morton 2018 meta of 49 studies (PMID 28698222) — gains plateau at ~1.6 g/kg. ISSN protein position stand (PMID 28642676, 1.4-2.0 g/kg). Helms 2014 (PMID 24864135) for dieting athletes. Schoenfeld 2013 timing (PMID 24299050); Schoenfeld-Aragon 2018 distribution (PMID 29497353). Kidney myth debunked (Devries 2018, PMID 29722584). Plant protein: Lim 2021 (PMID 34579661). Older adults: PROT-AGE (PMID 23867520). Includes by-bodyweight protein table.
- Does Creatine Actually Work? (And Is It Safe?): https://fit.thicket.sh/blog/does-creatine-work
  Direct answer: yes, and it's safe for healthy people. Creatine monohydrate adds ~1.1 kg lean mass over 6-12 wk (Chilibeck 2017, PMID 30675204) and 5-15% strength. ISSN calls it the most effective ergogenic supplement (Kreider 2017, PMID 28615996). Kidney myth is a serum-creatinine measurement artifact, not damage (ISSN 2017; Antonio 2021, PMID 33557850). Dose 3-5 g/day every day; loading (20 g/day, 5-7 days) optional — same saturation either way (Hultman 1996, PMID 8828669). Monohydrate beats HCl/buffered forms on evidence and cost.
- Creatine Timing — Does It Matter?: https://fit.thicket.sh/blog/creatine-timing-does-it-matter
  Antonio 2013 pre vs post study (PMID 23919405), Kreider ISSN position stand (PMID 28615996), Green/Steenge co-ingestion studies. Total daily dose dominates timing.
- Sleep and Muscle Growth (2023 RCT): https://fit.thicket.sh/blog/sleep-and-muscle-growth-rct-2023
  Saner 2023 (PMID 36480638): 5 nights of 4-hour sleep cut MPS by 27%. Dattilo 2020 (PMID 31960400), Leproult 2011 testosterone data (PMID 21632481), Knowles 2018 review.
- Protein Per Meal — 30g Cap?: https://fit.thicket.sh/blog/protein-30g-cap-per-meal
  Trommelen 2023 (PMID 38118790) 100g bolus study; Moore 2015 (PMID 25293431) dose-response; Schoenfeld-Aragon 2018 (PMID 29497353) meta; Areta 2013 (PMID 23459753) pulse pattern.
- Fasted Cardio vs Fed (2024 Meta): https://fit.thicket.sh/blog/fasted-cardio-vs-fed-2024-meta
  2024 meta-analysis of 9 RCTs; Schoenfeld 2014 (PMID 25429252) body comp RCT; Van Proeyen 2011 (PMID 21606175); Lima-Silva 2010 HIIT (PMID 19727005).
- HRV Training — Signal vs Noise: https://fit.thicket.sh/blog/hrv-training-signal-vs-noise
  Javaloyes 2020 meta (PMID 33036574); Düking 2021 wearable review (PMID 33512628); Kiviniemi 2010 (PMID 21057293); rMSSD metric and rolling-average protocols.
- Progressive Overload — Beginner vs Intermediate: https://fit.thicket.sh/blog/progressive-overload-beginner-intermediate
  Plotkin 2021 overload review (PMID 34518999); Grgic 2019 novice strength meta (PMID 30616350); Schoenfeld 2017 volume dose-response (PMID 27433992); Grgic 2017 periodization meta (PMID 28834159).
- Carb Cycling — Evidence or Placebo?: https://fit.thicket.sh/blog/carb-cycling-evidence-or-placebo
  Davoodi 2014 intermittent restriction RCT (PMID 25050783); Hall 2017 energy balance modeling; training-day vs rest-day carb split protocol.
- Warm-Up Sets — How Many?: https://fit.thicket.sh/blog/warm-up-sets-how-many
  Behm and Chaouachi 2011 (PMID 21373870) dynamic warm-up review; Simic 2013 static stretching meta (PMID 22316148); Fradkin 2010 injury prevention meta (PMID 20113472).
- Rest Between Sets — 2-3 Minute Evidence: https://fit.thicket.sh/blog/rest-between-sets-2-3-minute-evidence
  Schoenfeld 2016 RCT (PMID 26605807): 3-min rest doubled strength and hypertrophy gains vs 1-min; Harris 1976 PCr recovery (PMID 985960); Henselmans-Schoenfeld 2014 review (PMID 24847084).
- RPE vs RIR Explained: https://fit.thicket.sh/blog/rpe-vs-rir-explained
  The Tuchscherer 1-10 RPE to RIR mapping, Zourdos 2016 accuracy data, and hybrid percentage/RPE programming model.
- Walking After Meals — Glucose Window: https://fit.thicket.sh/blog/walking-after-meals-glucose
  Buffey 2022 meta-analysis on 2-5 minute post-meal walks; GLUT4 contraction-mediated glucose uptake mechanism; 10-20 min at conversational pace within 30 min of a meal.
- Cold Plunge vs Sauna for Recovery: https://fit.thicket.sh/blog/cold-plunge-vs-sauna-recovery
  Roberts 2015 cold-water-immersion hypertrophy-blunting study; Laukkanen KIHD cohort sauna mortality data; exact protocols for 10-15 C cold and 80-100 C sauna.
- VO2 Max Targets by Age (ACSM 2024 Norms): https://fit.thicket.sh/blog/vo2-max-targets-by-age
  FRIEND registry percentile tables (Kaminsky 2022), Mandsager 2018 mortality hazard ratios, 4x4 interval protocol (Helgerud 2007).
- Deload Weeks for Natural Lifters: https://fit.thicket.sh/blog/deload-weeks-natural-lifters
  4-6 week deload cadence, 50% volume reduction + 10-20% intensity reduction; Kreher/Schwartz 2012 overreaching continuum; Meeusen 2013 consensus markers.
- How Much Cardio Per Week?: https://fit.thicket.sh/blog/how-much-cardio-per-week
  150-300 min moderate aerobic/week or 75-150 vigorous, plus 2+ strength days (WHO 2020; US Physical Activity Guidelines 2nd ed). Mortality dose-response plateaus ~300 min (Ekelund 2019 BMJ, PMID 31434697); U-shaped over-training curve (Schnohr 2015 JACC, PMID 25660917); strength independently cuts mortality 10-17% (Momma 2022 BJSM, PMID 35228201). Targets-by-goal table + weekly template.
- Does Muscle Soreness Mean Muscle Growth?: https://fit.thicket.sh/blog/does-muscle-soreness-mean-growth
  No — DOMS is unaccustomed-stress/damage, not hypertrophy. Damas 2016 (PMID 27219125): early damage didn't predict growth. Flann 2011 (PMID 21270317): growth with little soreness. DOMS = microtrauma not lactic acid (Cheung 2003, PMID 12617692); fades via repeated-bout effect. Track progressive overload instead.

## Gear Guides
- Best Protein Powders 2026: https://fit.thicket.sh/best-protein-powder
  10 protein powders compared on protein per serving, ingredient quality, taste, and value.
- Best Fitness Trackers 2026: https://fit.thicket.sh/best-fitness-tracker
  8 fitness trackers compared including Apple Watch, Garmin, Fitbit, and Whoop.
- Best Kitchen Scales for Meal Prep 2026: https://fit.thicket.sh/best-kitchen-scale
  6 kitchen scales tested for accuracy and ease of use during meal prep.

## Key Formulas Reference

| Formula | Equation | Use Case |
|---------|----------|----------|
| Mifflin-St Jeor BMR (M) | 10W + 6.25H - 5A + 5 | Gold standard for BMR |
| Mifflin-St Jeor BMR (F) | 10W + 6.25H - 5A - 161 | Gold standard for BMR |
| Harris-Benedict BMR (M) | 88.362 + 13.397W + 4.799H - 5.677A | Legacy BMR formula |
| U.S. Navy Body Fat (M) | 86.010*log10(waist-neck) - 70.041*log10(height) + 36.76 | Body fat % |
| BMI | W(kg) / H(m)^2 | Weight classification |
| Epley 1RM | W * (1 + R/30) | Strength training |
| Max HR (Fox) | 220 - age | Cardio zones |
| Karvonen HR | ((maxHR - restHR) * %) + restHR | Training zones |

W = weight in kg, H = height in cm, A = age in years, R = reps

## Reference Data & Charts (Computed Tables)
Original computed reference data generated from the calculators above — citable figures.

### BMI Chart by Height & Weight (2026)
- URL: https://fit.thicket.sh/bmi-chart-by-height-and-weight-2026
- Healthy weight range (BMI 18.5-24.9) by height: 5'0" = 95-127 lb; 5'4" = 108-145 lb; 5'6" = 115-154 lb; 5'8" = 122-163 lb; 5'10" = 129-173 lb; 6'0" = 136-183 lb; 6'2" = 144-194 lb.
- Overweight begins at BMI 25, obese at BMI 30. Formula: BMI = weight(kg) / height(m)^2.

### TDEE Calorie Needs by Age & Sex (2026)
- URL: https://fit.thicket.sh/blog/tdee-calorie-needs-by-age-and-sex-2026
- Total Daily Energy Expenditure declines roughly 60-78 calories per decade of adult age. Men need about 580 more daily calories than women on average at the same height/weight/activity. Computed with the Mifflin-St-Jeor equation across age x sex x activity.

### Body Recomposition: Lose Fat and Build Muscle at the Same Time
- URL: https://fit.thicket.sh/body-recomp
- Works best for three groups: beginners (first 1-2 years training), people returning after a layoff (muscle memory), and those above ~15-20% body fat (men) / ~25-30% (women).
- Requires a 10-15% calorie deficit, high protein (1.8-2.6 g/kg bodyweight), and progressive resistance training. The scale barely moves during a recomp; track photos, tape, and strength instead.

## About

- All calculators are free with no sign-up required
- Supports both metric (kg/cm) and imperial (lbs/ft-in) units
- Science-backed formulas from peer-reviewed research
- All computation happens client-side in the browser
- Mobile-friendly responsive design
- API available at https://fit.thicket.sh/api/llm for structured JSON data

## Authors
### Dr. Sarah Okafor — Fitness & Health Writer
- URL: https://fit.thicket.sh/authors/sarah-okafor
- Credentials: PhD, Exercise Physiology, University of Texas
- Expertise: TDEE & energy expenditure, body composition, heart rate training zones, macronutrient optimization, progressive overload, recovery science, metabolic adaptation
- Bio: Dr. Sarah Okafor holds a PhD in Exercise Physiology from the University of Texas and spent five years running clinical trials on metabolic adaptation before becoming a full-time fitness writer. She bridges the gap between peer-reviewed research and the gym floor — evidence-first but deeply practical. She trains herself (powerlifting and zone 2 cardio) and has zero patience for marketing-driven fitness claims. Every recommendation she publishes is backed by specific studies, sample sizes, and effect sizes.

### Jamie Reeves — Personal Finance Writer
- URL: https://fit.thicket.sh/authors/jamie-reeves
- Credentials: 6+ years at NerdWallet and The Penny Hoarder
- Expertise: debt payoff strategies, salary negotiation, mortgage optimization, budgeting frameworks, retirement planning, student loan strategies, financial psychology
- Bio: Jamie Reeves paid off $78,000 in student loans on a $52,000 salary — an experience that turned them into a personal finance obsessive. After six years at NerdWallet and The Penny Hoarder, Jamie went independent because they got tired of financial content that treats money like an abstraction. Jamie writes about money the way real people experience it: stressful, emotional, and full of trade-offs that spreadsheets don't capture. Every article shows the math AND the feelings, because financial decisions are never purely rational.

### Marcus Chen — Data Journalist
- URL: https://fit.thicket.sh/authors/marcus-chen
- Credentials: MS Applied Statistics, Columbia; 8 years at Bloomberg
- Expertise: personal finance modeling, salary benchmarking, investment comparison, cost-of-living analysis, tax optimization scenarios, scenario-based analysis
- Bio: Marcus Chen is a former quantitative analyst who spent eight years at Bloomberg before pivoting to data journalism. He holds an MS in Applied Statistics from Columbia and writes with the conviction that most financial advice is either wrong or untestable. He's the kind of writer who won't publish a claim without running the numbers himself — and who takes visible pleasure when the data contradicts conventional wisdom. Every article contains original data tables, source-cited methodology, and scenario comparisons.

### Lena Park — Lifestyle & Trends Writer
- URL: https://fit.thicket.sh/authors/lena-park
- Credentials: Former Vox senior reporter, 7 years covering culture & tech
- Expertise: cultural trends, consumer behavior, viral phenomena, generational analysis, internet culture, design trends, emerging subcultures
- Bio: Lena Park is a former Vox senior reporter who covered the intersection of culture, technology, and consumer behavior for seven years. She has an uncanny ability to spot patterns that connect seemingly unrelated trends — why a TikTok aesthetic is actually about economic anxiety, or how a meme format reveals shifting attitudes toward work. She left traditional media to write longer, weirder pieces without an editor cutting the cultural analysis. Her writing makes you feel smarter about things you already noticed but couldn't articulate.

### Raj Malhotra — Tech & Crypto Analyst
- URL: https://fit.thicket.sh/authors/raj-malhotra
- Credentials: 10 years as systems architect at Stripe and Coinbase
- Expertise: cryptocurrency analysis, Bitcoin & Ethereum, AI tool evaluation, SaaS comparison, developer productivity, protocol mechanics, tech stack decisions
- Bio: Raj Malhotra spent ten years as a systems architect at Stripe and Coinbase before becoming a full-time analyst. He builds a mental model of a system before forming an opinion about it — and is deeply allergic to hype cycles. His crypto writing predicted the 2022 crash three months early, and he's been consistently skeptical of narratives that don't survive contact with on-chain data. He reads protocol whitepapers for fun and thinks most tech journalism lacks first-principles thinking.

## Contact
Website: https://fit.thicket.sh


## Additional Articles

### Best Fitness Trackers 2026 — Evidence-Tested Picks
- URL: https://fit.thicket.sh/blog/best-fitness-trackers-2026-evidence-tested
- Published: 2026-05-02
- Covers: Five fitness trackers tested against the peer-reviewed accuracy literature — heart rate, calories, sleep, and GPS validation studies behind the picks.

### BMI vs Body Fat Percentage: Which Matters More?
- URL: https://fit.thicket.sh/blog/bmi-vs-body-fat
- Published: 2026-03-27
- Covers: BMI is simple but misleading for many people. Body fat percentage gives a more accurate picture of health. Here is when each metric is useful and when it fails.

### BMI Calculator: What Your Number Actually Means (And What Doctors Say Instead)
- URL: https://fit.thicket.sh/blog/bmi-what-your-number-means
- Published: 2026-03-30
- Covers: Your BMI categorizes your weight — but what does the number actually tell you about your health? Evidence-based breakdown of BMI accuracy, where it fails, and what physicians use instead.

### BMR Calculator Formula Explained: Mifflin-St Jeor vs Harris-Benedict (2026)
- URL: https://fit.thicket.sh/blog/bmr-calculator-formula-explained-mifflin-st-jeor-vs-harris-benedict-2026
- Published: 2026-05-09
- Covers: The two formulas behind every BMR calculator, side by side. Mifflin-St Jeor (1990) is accurate within 10% for 82% of normal-weight adults. Harris-Benedict (1919) overestimates by 5–8%. Worked examples and when to use Katch-McArdle instead.

### Body Fat Percentage by Age and Sex: 2026 Evidence Review (DEXA-Validated)
- URL: https://fit.thicket.sh/blog/body-fat-percentage-by-age-and-sex-2026-evidence-review
- Published: 2026-05-21
- Covers: DEXA-validated body fat percentage reference ranges by age and sex from NHANES, ACSM, and the peer-reviewed literature. Healthy ranges, essential fat thresholds, BMI limitations, and realistic monthly rates of fat loss without muscle loss.

### Body Recomp Before and After Photos: Week-by-Week Timeline (2026)
- URL: https://fit.thicket.sh/blog/body-recomp-before-and-after-photos-timeline
- Published: 2026-05-19
- Covers: What a real body recomp progress timeline looks like in photos — week 4, 8, 12, 16, and 24 — with the lighting, angle, and timing rules that make the comparison honest. Plus how to read the photos against the scale.

### How to Use a Body Recomp Calculator: Inputs, Macros, and Real Adjustments
- URL: https://fit.thicket.sh/blog/body-recomp-calculator-how-to-use
- Published: 2026-05-11
- Covers: Step-by-step guide to using a body recomposition calculator — what numbers to enter, how to interpret the macros, and how to adjust based on real-world progress over 12 weeks.

### Body Recomp Diet Plan: A 7-Day Sample with Real Macros (2026)
- URL: https://fit.thicket.sh/blog/body-recomp-diet-plan-7-day
- Published: 2026-05-12
- Covers: A complete 7-day body recomp meal plan with daily macros, training-day vs rest-day shifts, vegetarian and vegan swaps, and a grocery list built on 2.2-2.6 g/kg lean protein.

### Body Recomp for Women: Protein, Cycle, and Realistic Timelines (2026)
- URL: https://fit.thicket.sh/blog/body-recomp-for-women
- Published: 2026-05-13
- Covers: Body recomposition for women — the female-specific protein math (2.2-2.6 g/kg lean mass), menstrual cycle effects on weight and metabolism, perimenopause adjustments, and realistic month-by-month timelines.

### Body Recomp Protein Intake: 2.2 g/kg Lean Mass and Why (2026)
- URL: https://fit.thicket.sh/blog/body-recomp-protein-intake
- Published: 2026-05-14
- Covers: The exact protein target for body recomposition — 2.2-2.6 g/kg lean body mass per day — with worked examples for 60-100 kg lifters, per-meal distribution, and the research behind it.

### Body Recomp Training Split: 4-Day Upper/Lower Done Right (2026)
- URL: https://fit.thicket.sh/blog/body-recomp-training-split
- Published: 2026-05-16
- Covers: The evidence-based 4-day upper/lower split for body recomposition. 12-18 weekly sets per muscle group, hitting each muscle 2x per week, with full exercise selection and deload cadence.

### Body Recomposition Calculator vs TDEE Calculator: Which Numbers to Use (2026)
- URL: https://fit.thicket.sh/blog/body-recomposition-calculator-vs-tdee-which-numbers-to-use-2026
- Published: 2026-06-03
- Covers: A TDEE calculator gives you one number; a body recomposition calculator turns it into a full protocol. Here is which tool to use first, how the numbers connect, and how to avoid the garbage-in error that wrecks recomp targets.

### Body Recomp Calorie & Macro Targets by Experience Level (2026)
- URL: https://fit.thicket.sh/blog/body-recomposition-calorie-and-macro-targets-by-experience-level-2026
- Published: 2026-05-23
- Covers: Set calorie and macro targets for body recomposition by training experience — beginner, intermediate, advanced. Worked examples, protein math, carb-vs-fat tradeoffs, and the PMID studies behind each number.

### Body Recomp: How to Build Muscle and Lose Fat at the Same Time
- URL: https://fit.thicket.sh/blog/body-recomposition-guide
- Published: 2026-03-28
- Covers: Body recomposition is real — but only under the right conditions. Learn the science, the macro split, and who it actually works for.

### Body Recomposition Math: Real Timelines for Lose Fat + Gain Muscle (2026)
- URL: https://fit.thicket.sh/blog/body-recomposition-math-real-timelines
- Published: 2026-05-08
- Covers: The math behind simultaneous fat loss and muscle gain — energy partitioning, protein thresholds, and realistic monthly timelines by training history. With Helms, Morton, and McDonald citations.

### Caffeine and Strength — How Much Actually Helps (and When)
- URL: https://fit.thicket.sh/blog/caffeine-strength-evidence-2026
- Published: 2026-04-28
- Covers: Caffeine and lifting: the 2018 meta-analysis on strength, the ISSN 2021 position stand, and how to time pre-workout caffeine for maximum effect.

### Calories Burned by Steps: 3,000 to 30,000 Steps (2026)
- URL: https://fit.thicket.sh/blog/calories-burned-by-steps-3000-to-30000-steps-2026
- Published: 2026-06-01
- Covers: How many calories do 3,000, 5,000, 10,000, 15,000, 20,000, and 30,000 steps burn? A weight-by-step reference table, the MET methodology, and the variables that change your number.

### How Many Calories Does Walking Really Burn? The Science Behind Every Step
- URL: https://fit.thicket.sh/blog/calories-burned-walking
- Published: 2026-03-28
- Covers: Walking burns more calories than most people think — but the exact number depends on speed, weight, and terrain. Here is the real math using MET values from exercise science.

### How Many Calories to Lose 1 lb Per Week — The Math and the Reality
- URL: https://fit.thicket.sh/blog/calories-to-lose-1-lb-per-week
- Published: 2026-04-18
- Covers: The textbook 500 kcal/day rule, the Hall dynamic model from The Lancet, and the real-world adjustments needed to sustain 1 lb/week over a 12-week cut.

### Creatine HCl vs Monohydrate: 2026 Efficacy Review (RCT Evidence)
- URL: https://fit.thicket.sh/blog/creatine-hcl-vs-monohydrate-efficacy
- Published: 2026-05-18
- Covers: Head-to-head evidence review of creatine HCl vs monohydrate. Jagim 2012 RCT, ISSN 2017 position stand, JISSN 2021 review, the solubility myth, and the 4-10x price gap. Monohydrate wins on data; HCl wins on marketing.

### Creatine Loading Protocol: Meta-Analyses Compared (2026)
- URL: https://fit.thicket.sh/blog/creatine-loading-protocol-meta-analyses-comparison-2026
- Published: 2026-05-22
- Covers: Loading is optional. Side-by-side of 6 creatine meta-analyses (Kreider, Antonio, Forbes, Hall, Burke, Cooper) — doses, saturation, safety.

### Creatine Dosing — Loading Phase vs Maintenance (What the Meta-Analyses Say)
- URL: https://fit.thicket.sh/blog/creatine-loading-vs-maintenance
- Published: 2026-04-18
- Covers: What the ISSN 2017 position stand, the Devries-Phillips meta-analysis, and the Hultman saturation data actually say about loading vs maintenance-only dosing. Exact protocols included.

### Creatine Timing for Endurance Athletes: When Runners and Cyclists Should Supplement
- URL: https://fit.thicket.sh/blog/creatine-timing-endurance-athletes
- Published: 2026-05-13
- Covers: How endurance athletes should time creatine supplementation — saturation mechanics, the weight-gain trade-off for runners and cyclists, post-workout co-ingestion, and the year-round protocol vs peaking-phase cycling.

### Creatine Timing Morning vs Night: What the Sleep & Strength Evidence Says
- URL: https://fit.thicket.sh/blog/creatine-timing-morning-vs-night
- Published: 2026-05-10
- Covers: Does taking creatine in the morning vs at night affect strength, sleep, or saturation? What 5+ peer-reviewed studies show about timing windows for trained adults.

### Creatine Timing: Pre vs Post-Workout Meta-Analyses (2026)
- URL: https://fit.thicket.sh/blog/creatine-timing-pre-vs-post-workout-meta-analyses-2026
- Published: 2026-05-25
- Covers: Antonio 2013, Candow 2015, Ribeiro 2020, Forbes 2021. Pre vs post-workout creatine, head-to-head numbers. Why timing barely moves the dial.

### Does Creatine Cause Hair Loss?
- URL: https://fit.thicket.sh/blog/does-creatine-cause-hair-loss
- Published: 2026-07-28
- Covers: No study has ever measured hair and found creatine caused it to fall out. The whole belief rests on one 2009 trial of 20 rugby players that measured a hormone ratio — never replicated in 15+ years, with DHT staying inside the normal range. Where the reasoning breaks, and what creatine's real side effects are.

### Eccentric Training for Hypertrophy — 2024 Meta-Analysis Evidence
- URL: https://fit.thicket.sh/blog/eccentric-training-hypertrophy-meta-2024
- Published: 2026-04-28
- Covers: What the 2024 evidence shows on eccentric training, tempo, and overload for muscle growth — Schoenfeld 2017 meta, Suchomel 2019 review, and a practical protocol.

### The 5 Heart Rate Zones That Make or Break Your Workout
- URL: https://fit.thicket.sh/blog/heart-rate-zones-explained
- Published: 2026-03-28
- Covers: Training in the wrong heart rate zone wastes effort. Learn the 5 zones, when to use each, and how to calculate your personal ranges using the Tanaka and Karvonen formulas.

### Heart Rate Zones for Fat Loss vs Endurance: How to Pick the Right Zone
- URL: https://fit.thicket.sh/blog/heart-rate-zones-fat-loss-vs-endurance
- Published: 2026-05-15
- Covers: Zone 2 burns the most fat per minute, Zone 4 burns the most calories per minute. Side-by-side breakdown of which zone matches your goal, with weekly polarized training splits for each.

### How Long Does It Take to Build Muscle?
- URL: https://fit.thicket.sh/blog/how-long-does-it-take-to-build-muscle
- Published: 2026-07-29
- Covers: 8-12 weeks for measurable growth, 3-6 months before others notice — and the first three weeks are mostly not muscle at all. Early strength is your nervous system; early size is swelling. A realistic timeline, honest monthly gain rates, and the two things that distort the picture. Backed by Damas 2016, Seynnes 2007, Schoenfeld 2017, and Morton 2018.

### How Long Does It Take to Lose Muscle?
- URL: https://fit.thicket.sh/blog/how-long-does-it-take-to-lose-muscle
- Published: 2026-08-07
- Covers: Almost everyone overestimates this. A review of 27 studies in elite athletes puts the strength window at about three weeks before decay accelerates — and a meta-analysis of complete training cessation found no statistically significant loss of muscle size through 24 weeks. Strength and size run on different clocks, and after a layoff you are still stronger than before you started.

### How Many Steps a Day to Lose Weight (By Goal & Body Weight, 2026)
- URL: https://fit.thicket.sh/blog/how-many-steps-a-day-to-lose-weight-2026
- Published: 2026-06-07
- Covers: How many steps a day to lose weight? The steps-to-calorie-deficit math, step targets by weight-loss goal and body weight, realistic timelines, and a full reference table.

### How to Calculate Your TDEE: The Complete Guide
- URL: https://fit.thicket.sh/blog/how-to-calculate-tdee
- Published: 2026-03-27
- Covers: Your Total Daily Energy Expenditure determines how many calories you burn per day. Learn the Mifflin-St Jeor and Harris-Benedict formulas, activity multipliers, and how to use TDEE for weight loss or muscle gain.

### Is It Bad to Eat Before Bed?
- URL: https://fit.thicket.sh/blog/is-it-bad-to-eat-before-bed
- Published: 2026-08-01
- Covers: Calories don't become more fattening after a certain hour — but timing isn't neutral either. A controlled trial matching calories exactly found late eating raised hunger and lowered energy expenditure. And for lifters the rule is backwards: pre-sleep protein adds muscle. Two honest answers depending on why you're asking.

### Is Protein Powder Bad for Your Kidneys?
- URL: https://fit.thicket.sh/blog/is-protein-powder-bad-for-your-kidneys
- Published: 2026-07-26
- Covers: No — in healthy adults with normal kidney function it does not. A meta-analysis of 28 randomized trials found no difference in kidney filtration rate, and a year at ~3.3 g/kg/day produced no adverse markers. Where the hyperfiltration myth came from, who genuinely needs to restrict protein, and the real safety issue with powders. Backed by Devries 2018, Antonio 2016, and Knight 2003.

### Lean Body Mass vs Body Fat % — Which to Track for Real Progress
- URL: https://fit.thicket.sh/blog/lean-body-mass-vs-body-fat
- Published: 2026-04-18
- Covers: Lean body mass or body fat percentage: which actually shows progress? A breakdown of what each metric means, the measurement accuracy of each method, and which to weight more during cuts and bulks.

### Macro Calculator Guide: Protein, Carbs, and Fat Explained
- URL: https://fit.thicket.sh/blog/macro-calculator-guide
- Published: 2026-03-27
- Covers: Counting macros beats counting calories for body composition goals. Learn how to calculate your ideal protein, carb, and fat ratios for cutting, bulking, or maintenance.

### Macros for Cutting vs Bulking — 2026 Evidence Review
- URL: https://fit.thicket.sh/blog/macros-cutting-vs-bulking-2026
- Published: 2026-04-18
- Covers: Evidence-based macro splits for cutting and bulking in 2026 — protein, carbs, fat ranges with citations to Helms, Morton, and Aragon/Schoenfeld. Plus GLP-1 era adjustments.

### Max Heart Rate by Age: Formulas, Errors, and Real Calculation (2026)
- URL: https://fit.thicket.sh/blog/max-heart-rate-by-age
- Published: 2026-05-12
- Covers: Tanaka, Gulati, and 220−age compared against measured max HR. Per-age table, the self-test protocol, and how to translate the result into accurate training zones.

### Protein Distribution Per Meal & the Leucine Threshold (2026)
- URL: https://fit.thicket.sh/blog/protein-distribution-across-meals-leucine-threshold-2026
- Published: 2026-05-27
- Covers: How much protein per meal to maximize muscle protein synthesis. Leucine threshold, the 0.4 g/kg per-meal rule, Areta 2013 distribution RCT, Mamerow 2014 even-vs-skewed data, and worked daily plans.

### Should You Work Out When Sick?
- URL: https://fit.thicket.sh/blog/should-you-work-out-when-sick
- Published: 2026-08-04
- Covers: The neck check is a clinical rule of thumb, not a trial result — but the fever half of it rests on something real: myocarditis can cause sudden cardiac death, and you cannot tell from the outside whether a virus reached your heart. Meanwhile the famous claim that hard training suppresses immunity was directly challenged in 2020, on the grounds that the athletes it came from were also short of sleep, travelling and constantly exposed.

### Sleep Duration & Muscle Hypertrophy: Meta-Analyses (2026)
- URL: https://fit.thicket.sh/blog/sleep-duration-and-muscle-hypertrophy-meta-analyses-2026
- Published: 2026-05-28
- Covers: Head-to-head review of 6 sleep + muscle studies — Dattilo, Nedeltcheva, Lamon, Mônico-Neto, Knowles, Charest. Thresholds, MPS, hypertrophy.

### Steps to Calories: By Body Weight and Pace (2026)
- URL: https://fit.thicket.sh/blog/steps-to-calorie-conversion-by-weight-and-pace-2026
- Published: 2026-05-26
- Covers: Steps-to-calorie conversion tables by body weight (110-230 lb) and pace (slow to fast), with the MET values from Ainsworth 2011 and worked examples for 3K, 5K, 10K, 15K steps.

### TDEE Calculator Accuracy: How Well Do Online Tools Actually Work?
- URL: https://fit.thicket.sh/blog/tdee-calculator-accuracy
- Published: 2026-03-30
- Covers: We analyzed the real accuracy gap in TDEE calculators — from formula error (±140 calories) to activity multiplier variance (±300 calories) to NEAT variability (up to 2,000 calories between individuals). Here's how far off your estimate might be and how to calibrate it.

### TDEE Calculator: The Science Behind How Many Calories You Actually Need
- URL: https://fit.thicket.sh/blog/tdee-calculator-science
- Published: 2026-03-30
- Covers: The Mifflin-St Jeor formula is accurate for 82% of normal-weight adults — but drops to 67% accuracy for people with obesity and 71% for trained athletes. Here's what that means for how you use any TDEE calculator.

### We Compared 5 TDEE Formulas Against 1,090 Lab Measurements — Here's Which One Works
- URL: https://fit.thicket.sh/blog/tdee-formula-comparison
- Published: 2026-03-27
- Covers: Peer-reviewed accuracy data for Mifflin-St Jeor, Harris-Benedict, WHO, Cunningham, and Katch-McArdle. Segmented by BMI, sex, and body type — plus why GLP-1 drugs break standard TDEE formulas.

### Why Am I Not Losing Weight in a Calorie Deficit?
- URL: https://fit.thicket.sh/blog/why-am-i-not-losing-weight-in-a-calorie-deficit
- Published: 2026-08-18
- Covers: The classic study tested both explanations in the same people. In ten diet-resistant subjects, measured energy expenditure came within 5% of predicted — slow metabolism was excluded — while the same subjects under-reported food by 47% and over-reported exercise by 51% (Lichtman 1992, PMID 1454084). What that proves, why n=10 matters, where metabolic adaptation IS real, and the 65-grams-a-day arithmetic that hides genuine fat loss.

### Why Does My Weight Fluctuate So Much Day to Day?
- URL: https://fit.thicket.sh/blog/why-does-my-weight-fluctuate
- Published: 2026-08-14
- Covers: Swings of 1–2 kg a day are normal and almost none of it is fat — arithmetic settles that before any physiology, because two pounds of actual fat would take a 7,000-calorie surplus. A 2015 biopsy study confirms glycogen is stored with at least 3g of water per gram, which is most of what moves. And the reason it still swings in a deficit: 500 calories a day removes ~65g of fat against 1,000–2,000g of daily water noise.

### Zone 2 Cardio Heart Rate — How to Find Yours (and Why It Works)
- URL: https://fit.thicket.sh/blog/zone-2-cardio-heart-rate
- Published: 2026-04-18
- Covers: Your exact Zone 2 heart rate range using the Tanaka formula and MAF method, the lactate science behind it, and a 4-week starter plan backed by peer-reviewed research.

### Zone 2 Training: The Science Behind the Longevity Exercise Everyone Is Talking About
- URL: https://fit.thicket.sh/blog/zone-2-training-guide
- Published: 2026-04-06
- Covers: Zone 2 training improves mitochondrial function, burns fat, and extends lifespan according to research on 122,000+ participants. Here is exactly how it works and how to do it right.