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Body Fat Percentage Calculator
Estimate your body fat percentage with the US Navy tape-measure method. You need your height, neck and waist — and hip, for women.
Free · no signup · updated August 2026
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How the US Navy method works
The Navy circumference method estimates body density from the places fat actually accumulates — the waist (and hips, for women) — corrected by neck girth and height, using log-transformed tape measurements. It was validated against underwater weighing across thousands of service members and typically lands within 3–4 percentage points of a DEXA scan, which makes a €2 tape measure competitive with consumer body-fat scales.
| Category | Men | Women |
|---|---|---|
| Essential fat | 2–5% | 10–13% |
| Athletic | 6–13% | 14–20% |
| Fit / healthy | 14–20% | 21–28% |
| Above typical | 21–25% | 29–32% |
| High | 25%+ | 33%+ |
Measurement discipline decides the accuracy: same time of day, tape snug but not compressing, and the average of two or three readings. The number that matters is the monthly trend, not any single morning.
Frequently asked questions
How accurate is the Navy body fat method?
Within about 3–4 percentage points for most people when measurements are taken carefully — comparable to consumer bioimpedance scales and far better than BMI alone at describing composition. DEXA scans remain the accurate reference.
How do I measure correctly?
Use a flexible tape, snug but not compressing. Neck: just below the larynx, tape sloping slightly down at the front. Waist: for men at the navel, for women at the narrowest point. Hips (women): at the widest point. Measure relaxed, not sucked in.
What is a healthy body fat percentage?
Typical healthy ranges are roughly 10–20% for men and 18–28% for women, rising a little with age. Athletes run lower; essential fat is about 3% for men and 12% for women — going near those levels is neither necessary nor healthy for most people.
Why does the result change day to day?
The inputs move: hydration, food in the gut and tape placement all shift centimetres. Measure at the same time of day, average two or three readings, and watch the monthly trend — exactly what a diary is for.
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Estimates for general information only, not medical advice. BMR/TDEE use the Mifflin-St Jeor equation; individual needs vary.
