Body Fat Calculator
Estimate your body fat percentage with a tape measure, using the US Navy method — plus your fat mass and lean mass.
For healthy adults. These are estimates, not medical advice. Ask a doctor or dietitian about your own targets — especially if you are pregnant, have a health condition or are under 18.
US Navy body fat formula
The US Navy method estimates body fat from a few circumferences and your height. You only need a tape measure.
women: 495 ÷ (1.29579 − 0.35004 × log₁₀(waist + hips − neck) + 0.22100 × log₁₀(height)) − 450
(all measurements in cm)
Example: a man of 175 cm with an 86 cm waist and a 38 cm neck has about 17.7% body fat.
How to measure
- Waist: horizontally at the navel (men) or at the narrowest point (women), relaxed, after breathing out.
- Neck: just below the larynx, with the tape sloping slightly down to the front.
- Hips (women): at the widest point of the buttocks.
Body fat categories (ACE)
| Category | Women | Men |
|---|---|---|
| Essential fat | 10–13% | 2–5% |
| Athletes | 14–20% | 6–13% |
| Fitness | 21–24% | 14–17% |
| Average | 25–31% | 18–24% |
| Obese | 32% or more | 25% or more |
Tape-based methods are usually within a few percentage points of lab methods such as DEXA. Measure the same way each time to track change.
Frequently asked questions
How do I calculate body fat percentage at home?
Measure your waist, neck (and hips for women) and enter them with your height. The US Navy formula gives an estimate within a few percent.
What is a healthy body fat percentage?
According to the American Council on Exercise, about 14–24% for men and 21–31% for women are in the fitness and average ranges.