Body Fat Calculator
Estimate your body fat percentage with nothing more than a tape measure, using the U.S. Navy circumference method, and see which fitness category it falls in.
Estimate your body fat
How to measure
| Measurement | Where |
|---|---|
| Height | Barefoot, standing tall against a wall. |
| Neck | Just below the Adam’s apple, with the tape sloping slightly down at the front. |
| Waist — men | Around the belly at the level of the navel. |
| Waist — women | At the narrowest part of the waist, usually just above the navel. |
| Hips — women | Around the widest part of the buttocks. |
Body fat categories (American Council on Exercise)
| Category | Men | Women |
|---|---|---|
| Essential fat | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Obese | 25% and over | 32% and over |
How it is calculated
86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76
163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387
all measurements in inches (centimetres are divided by 2.54)
The U.S. Navy method (Hodgdon and Beckett, Naval Health Research Center) usually lands within a few percentage points of lab methods. It is best for tracking your own trend over time with the same tape and technique.
A result is rounded to one decimal place before its category is read. Values between two published bands (for example 5.5% for a man) fall into the higher band.
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For general information only — not medical advice, diagnosis or treatment. These calculators use population formulas that cannot account for every individual, and are meant for adults unless stated. Always speak to a qualified doctor about your health, and never delay seeking care because of a result here.