Know your numbers.
Own your health.
A complete suite of accurate health and fitness calculators — BMI, metabolism, calories, body fat and more — each paired with a plain-English guide on what your results actually mean.
Every calculator you need, in one place
Pick a tool to get an instant result, then read the guide below it to understand and act on your numbers.
BMI Calculator
Body Mass Index from height and weight, with your healthy weight range and category.
Calculate BMI →BMR Calculator
The calories your body burns at complete rest — your metabolic baseline.
Find your BMR →Calorie Calculator
Daily maintenance calories (TDEE) plus targets for losing or gaining weight.
Get calorie targets →Body Fat Calculator
Estimate body fat percentage with the U.S. Navy circumference method.
Estimate body fat →Ideal Weight
Target weight from four trusted clinical formulas and your healthy BMI band.
Find ideal weight →Macro Calculator
Turn a calorie target into daily protein, carbs and fat for your goal.
Split your macros →Numbers are easy. Knowing what to do with them is the hard part.
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Trusted formulas
Every tool uses the same peer-reviewed equations clinicians and dietitians rely on — Mifflin-St Jeor, the U.S. Navy method, Devine and more.
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Context, not just a number
Each result comes with a long-form guide: what the figure means, how it's calculated, its limits, and the concrete next step.
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Fast & private
Results compute instantly in your browser. No accounts, no waiting, and your measurements never leave your device.
Begin with the one number most people check first
Your BMI takes ten seconds and is the gateway to the rest of the toolkit.
Calculate my BMI