UltimateTools
Health & Wellness

Body Fat Calculator

Estimate your body fat percentage using the US Navy tape-measure method from your height, neck, waist, and hip measurements.

Estimated body fat

16.4%

Fitness

Uses the US Navy tape-measure method. Measure your neck just below the larynx, your waist at the navel, and (for the female formula) your hips at their widest point, for best accuracy.

How the Body Fat Calculator works

Using your height, neck, and waist measurements (plus hip for the female formula), the calculator applies the US Navy circumference method — a logarithmic formula developed for military fitness assessments — to estimate body fat percentage without special equipment.

Frequently asked questions

How accurate is the US Navy method?

It's typically accurate within about 3–4% body fat for most people compared to more precise methods like DEXA scans — accurate enough for tracking trends over time.

Where exactly should I measure?

Neck: just below the larynx (Adam's apple). Waist: at the navel. Hip (for the female formula): at the widest point of the hips. Measure snugly but without compressing the skin.

Why does the formula differ by gender?

Body fat distribution differs between men and women on average, so the US Navy method uses separate formulas — and an additional hip measurement — for women.