Health & Fitness

Body Fat vs. BMI

Compare body-fat percentage and body mass index and learn what each estimate can and cannot tell you.

Reference guidePlain-language explanationFree calculator included
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Body Fat Calculator

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Two different estimates

BMI uses only height and weight, while body-fat estimates try to describe body composition more directly.

Two people can have the same BMI and very different body-fat percentages, which is why the estimates answer different questions.

How to use this information

Use the guide to understand the method, then open the calculator to substitute your own values. Small differences in assumptions can produce different answers, so these pages are best used for planning and reference.

General information only: ERICH Calculators provides general-purpose estimates and education. It is not a substitute for professional medical advice, diagnosis or treatment.

Frequently asked questions

Is this an exact medical or nutrition recommendation?

No. It is a general reference estimate only.

Why might two methods give different answers?

Different methods use different assumptions, formulas and reference points.

What calculator should I use next?

Use the linked calculator to enter your own measurements or goals.

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