Body Fat Calculator
Estimate your body fat percentage using the US Navy circumference method.
Your measurements
Updates as you typeCategory reference
| Category | Men | Women | Where it sits |
|---|---|---|---|
| Essential Fat | 2–5% | 10–13% |
|
| Athletes | 6–13% | 14–20% |
|
| Fitness | 14–17% | 21–24% |
|
| Average | 18–24% | 25–31% |
|
| Obese | 25%+ | 32%+ |
|
Ranges are from the American Council on Exercise (ACE). Your current row lights up on the left.
How to measure
Get within ±1 cm for a trustworthy estimateJust below the larynx (Adam's apple). Keep the tape level and don't flex the neck.
Men: at the navel. Women: at the narrowest point. Tape horizontal — don't suck in.
Around the widest point of the buttocks, feet together and tape level.
Standing barefoot, heels together, head level. Measure on a hard floor.
Formula
- BF%
- Body fat percentage (of total body mass)
- waist
- Abdominal circumference in cm (at navel for men, narrowest for women)
- neck
- Neck circumference in cm, just below the larynx
- hip
- Hip circumference in cm at the widest point (female formula only)
- height
- Standing height in cm
- waist − neck = — cm
- log10(waist − neck) = —
- log10(height) = —
- Term A = —
- Term B = —
- BF% = —
The Navy method is quick and repeatable but trades accuracy for convenience: it can miss true body fat by 3–4 percentage points versus DEXA or hydrostatic weighing, and is most reliable for typical adult builds. Very muscular or very lean physiques tend to be over-estimated. Measure at the same time of day, post-bathroom, and before eating to keep readings comparable.