Science-based fitness calculators
Free Fitness Calculators for Lean Bulk, Body Recomposition & More
No signup, instant results. Enter your numbers and get your calorie target, macros, protein, body fat and a realistic timeline, all backed by the same equations the research uses.
- Mifflin-St Jeor & Katch-McArdle
- Metabolism-aware projections
- Runs in your browser, nothing stored
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The calculators most people want
Featured calculator
01Lean Bulk Calculator
Get your lean bulk calories and macros, then compare a +200, +300 and +400 kcal surplus with an honest verdict on how fast to gain.
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02Calorie Deficit Calculator
Get your daily calorie target and a realistic date to reach your goal weight, then compare deficit scenarios side by side.
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03Body Recomposition Calculator
See your calories and macros for building muscle and losing fat at the same time, plus an honest verdict on whether recomp is realistic for you.
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Dial in every number
- 04 TDEE Calculator Estimate the total calories you burn each day (your maintenance calories) using the Mifflin-St Jeor or Katch-McArdle equation.
- 05 Macro Calculator Turn your calories into daily protein, carb and fat targets for cutting, maintaining, lean bulking or recomp.
- 06 Protein Intake Calculator Find how much protein to eat per day, in grams, based on your bodyweight and your goal.
- 07 Body Fat Percentage Calculator Estimate your body fat percentage at home with the US Navy tape-measure method, no calipers needed.
Method & sources
The science behind the numbers
Every formula explained in plain English: what our metabolism-aware projection does differently, what it does not model, and the studies behind it.