Fast, accurate fitness calculators — no fluff, just numbers
10 science-backed calculators for nutrition, body composition, and strength. No sign-ups, no ads, just accurate numbers.
Calculate your Total Daily Energy Expenditure using Mifflin-St Jeor and Harris-Benedict equations with activity multipliers.
Calculate now →Find your Basal Metabolic Rate — the calories your body burns at complete rest using the Mifflin-St Jeor formula.
Calculate now →Get your ideal protein, carb, and fat split based on your TDEE and fitness goal — lose fat, maintain, or build muscle.
Calculate now →Plan your calorie intake for weight loss or muscle gain. See weekly targets and estimated timelines.
Calculate now →Estimate your body fat percentage using the U.S. Navy circumference method with waist, neck, and hip measurements.
Calculate now →Calculate your optimal daily protein intake based on body weight, activity level, and fitness goal.
Calculate now →Calculate your Body Mass Index and see where you fall on the WHO classification scale from underweight to obese.
Calculate now →Find your ideal body weight using Devine, Robinson, Miller, and Hamwi formulas side by side.
Calculate now →Estimate your one-rep max for any lift using Epley, Brzycki, and Lombardi formulas plus percentage chart.
Calculate now →Calculate how much water you should drink daily based on weight, activity level, and climate factors.
Calculate now →Every calculator uses peer-reviewed scientific formulas like Mifflin-St Jeor, Harris-Benedict, and the U.S. Navy body fat method. No made-up math.
No loading screens, no sign-up walls. Enter your data, hit calculate, and get your numbers immediately in your browser.
Built for phones first, works perfectly on any device. Quick access at the gym, at home, or wherever you need it.