All calculators
13 free tools, all based on standard formulas from the scientific literature (Mifflin-St Jeor, Katch-McArdle, Riegel, Tanaka, Karvonen, Epley/Brzycki). They run in your browser: your data never leaves your device. No signup, no intrusive ads.
Nutrition
Maintenance calories, macro split, deficit, daily protein, hydration and intermittent fasting: everything you need to build a diet that matches your goal.
- Calorie calculatorFree calorie calculator: find out how many calories you need per day to maintain, lose or gain weight. Uses the Mifflin-St Jeor formula and accounts for your age, weight, height and activity level.
- Macros calculatorFree macros calculator: compute your daily grams of protein, carbs and fat for your goal (cut, maintenance or bulk). Includes kcal per macro and evidence-based ranges from ISSN/EFSA.
- BMI calculatorFree online BMI (Body Mass Index) calculator. Enter your weight and height to get your BMI and your WHO classification: underweight, normal, overweight or obesity.
- Protein calculatorFree protein calculator: how many grams of protein you need per day based on your weight and goal (sedentary, hypertrophy, cut or athlete). Ranges based on ISSN, EFSA and recent meta-analyses.
- Calorie deficitCompute the daily calorie deficit to lose X kg in Y weeks, or the time needed for a given deficit. 1 kg of fat ≈ 7700 kcal.
- Daily water intakeHow much water you should drink per day based on your weight, physical activity and climate. Recommendations based on EFSA and ACSM.
- Intermittent fastingCompute your fasting and eating windows by protocol: 16:8, 18:6, 20:4, OMAD, 5:2 or alternate-day fasting.
- Body compositionEstimate your body-fat % with the Navy method (tape measure). You only need to measure neck and waist (and hips for women).
Strength training
1RM estimation, percentage tables and progression templates so every session pushes in the right direction.
Cardio & running
Running pace, Riegel predictions and heart-rate zones to train at the right intensity in every session.
Competition
Specific tools for functional competitions like Hyrox: time prediction, required pace and station-by-station breakdown.