These nine calculators cover the numbers athletes track most: how much you can lift, how fast you can run, and how much energy you burn doing it. Each one uses standard published formulas — Epley and Brzycki for one rep max, MET tables for calorie burn, and validated heart rate equations — so your results are comparable with what a coach or training app would give you.
Every calculator that involves weight, distance or speed supports metric and imperial. Enter kilograms or pounds, kilometres or miles, and results convert automatically. Pace calculators show min/km and min/mile side by side, which is handy when your race uses one system and your training watch uses the other.
Formulas like 1RM predictions and calorie burn estimates are population averages. They're accurate enough to plan training around, but individual results vary with technique, muscle fibre composition and fitness level. Treat the outputs as a well-informed starting point and adjust based on how your body actually responds.
Fitness and health metrics overlap heavily. The protein intake calculator pairs naturally with the TDEE and calorie deficit calculators in our health category, and max heart rate feeds directly into training zone planning. Cross-links on each page take you to the most relevant companion tools.