Body Fat Calculator

Estimate your body fat percentage with just a tape measure. Scales tell you total weight, but not what it is made of — two people at 80 kg can have very different body fat. The US Navy circumference method uses your height, neck, waist (and hips for women) to estimate body fat percentage, with no calipers, scales, or scans needed.

Gender

Height (cm)

Neck (cm, below the Adam’s apple)

Waist (cm, at the navel, relaxed)

How to Use the Body Fat Calculator

Select your gender — the hip measurement field appears automatically for women.
Measure your height, neck, and waist in cm. Measure the waist at the navel, relaxed and breathing normally — not sucked in.
Women also measure hips at the widest point around the buttocks.
Press Calculate for your estimated body fat percentage and its category.

Practical example

A man who is 180 cm tall with a 40 cm neck and 85 cm waist gets about 14.5% body fat — the “Fit” category, typical of someone who trains regularly. A woman 165 cm tall with a 34 cm neck, 75 cm waist, and 95 cm hips gets about 26.4% — the “Average” range for women, since healthy female body fat is naturally higher than male. Re-measure monthly with the same tape position to track real trends instead of day-to-day noise.

Key features and benefits

US Navy method: the best-validated tape-measure formula, used by the military for decades.
Category included: see where you fall — essential, athletic, fit, or average.
Measurement checks: catches impossible inputs (like a waist smaller than the neck) before calculating.
No equipment: a simple tape measure is all you need.
Private: your measurements never leave your browser.

Limitations

This is an estimate, typically within 3–4% of clinical DEXA scans — tape placement, posture, and whether you measured after a meal all affect accuracy. It is less reliable for very muscular bodies (large necks skew it), very lean bodies, and during pregnancy. For medical decisions or precise tracking, use clinical methods like DEXA or hydrostatic weighing instead. Consistency matters more than perfection: measure at the same time of day, before eating, with the tape level and snug but not compressing the skin.