How does the Navy body fat method work?

It estimates body fat from tape measurements of the neck and waist (and hips for women) plus height, using a formula validated by the U.S. Navy. It is free, needs only a tape measure, and is reasonably accurate for most people.

How accurate is the Navy method?

It is typically within 3-4 percentage points of DEXA for average builds, and best for tracking change over time with consistent measuring technique. It's less accurate at extremes of body composition.

Body Fat Calculator

Q: What is a healthy body fat percentage?

For men, roughly 10%-20% is fit and 2%-5% is essential fat; for women, 18%-28% is fit and 10%-13% is essential. Women naturally carry more essential fat. Athletes often sit at the lower ends of these ranges.

Estimate your body fat percentage with the U.S. Navy tape-measure method — no scale or scan needed, just a soft measuring tape.

Estimated body fat

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How to measure

Use a soft tape, relaxed and level, not compressing the skin. Neck: just below the larynx. Waist: at the navel for men, at the narrowest point for women. Hips (women): at the widest point. Measure on bare skin, exhale normally, and take the average of two readings.

Men: 495 ÷ (1.0324 − 0.19077·log₁₀(waist−neck) + 0.15456·log₁₀(height)) − 450
Women: 495 ÷ (1.29579 − 0.35004·log₁₀(waist+hip−neck) + 0.22100·log₁₀(height)) − 450

Body fat categories

Category	Men	Women
Essential fat	2–5%	10–13%
Athletes	6–13%	14–20%
Fitness	14–17%	21–24%
Average	18–24%	25–31%
Obese	25%+	32%+

Body fat percentage tells you something BMI can't — how much of your weight is fat versus muscle. It's the better metric for tracking a recomposition (losing fat while keeping or building muscle), where the scale can barely move while your body changes. Use consistent technique and compare trends, not single readings. Pair with the lean body mass and BMI calculators for a fuller picture.

Frequently asked questions

How does the Navy method work?

It estimates body fat from neck, waist (and hip for women) tape measurements plus height.

What is a healthy body fat percentage?

Men ~10–20% fit; women ~18–28%. Women carry more essential fat.

How accurate is it?

Usually within 3–4 points of DEXA; best for tracking change with consistent technique.

Related calculators

Medical disclaimer: A tape-based estimate, not a clinical measurement. Not medical advice. For precise body composition, consider DEXA or hydrostatic testing. Formula: U.S. Navy circumference method. Last reviewed: July 2026.