Free Fitness & Health Calculators

Nine science-based calculators for training, nutrition and body composition. Everything runs in your browser — no signup, no downloads.

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How to use these calculators

Each calculator is a single-purpose tool: enter your numbers and get an instant result. Every formula is published below its calculator, so you can check the math yourself. Nothing is stored or sent anywhere — all calculations happen locally in your browser.

Start with the TDEE & Calorie Calculator if you want a starting point for your nutrition plan, or the BMI Calculator for a quick body-composition snapshot.