How accurate is the Navy method?

It's reasonably accurate for most people (typically within a few percentage points of more precise methods like DEXA scans), making it a convenient estimate without special equipment.

Why does the formula need a hip measurement for women but not men?

Body fat distribution differs by sex, and the Navy method's female formula was calibrated to include hip circumference for better accuracy.

Body Fat Calculator

Estimate your body fat percentage using the U.S. Navy circumference method — just a tape measure needed, no calipers or scans required.

Sex

Height

Neck circumference

Waist circumference

Estimated Body Fat

10.6%

Athletic

How It Works

The circumference method

This method estimates body fat from circumference measurements (neck and waist for men; neck, waist, and hip for women) along with height, using a formula developed for the U.S. Navy's body composition standards.

Measuring correctly

Measure your neck just below the larynx, your waist at the navel, and (for women) your hips at the widest point — consistent measurement technique matters more for accuracy than any single formula.

Example Calculation

A man who is 180cm tall with a 38cm neck and 85cm waist has an estimated body fat of around 13-14%, in the "Athletic" range.

Common Mistakes

Measuring inconsistently (e.g. after eating, or with the tape too loose/tight) — small measurement errors shift the result noticeably.
Forgetting the hip measurement for the female formula, which requires it.
Treating this as a precise clinical measurement — circumference methods are an estimate, not as accurate as DEXA scans or hydrostatic weighing.

Frequently Asked Questions

How accurate is the Navy method?: It's reasonably accurate for most people (typically within a few percentage points of more precise methods like DEXA scans), making it a convenient estimate without special equipment.
Why does the formula need a hip measurement for women but not men?: Body fat distribution differs by sex, and the Navy method's female formula was calibrated to include hip circumference for better accuracy.