Body Fat Calculator

Estimate your body fat percentage using the U.S. Navy tape-measure method.

Body Fat Categories

Men

Essential fat2–5%
Athletic6–13%
Fitness14–17%
Average18–24%
Obese25%+

Measure with a flexible tape at the narrowest point of your waist and neck, and (for women) the widest point of your hips. This method is an estimate — DEXA scans or calipers are more precise.

The U.S. Navy Method

Developed by the U.S. Navy for fitness assessments, this method estimates body fat percentage from simple circumference measurements (neck, waist, and — for women — hips), rather than requiring specialist equipment like calipers or a DEXA scan.

Men: %BF = 495 / (1.0324 − 0.19077×log₁₀(waist−neck) + 0.15456×log₁₀(height)) − 450
Women: %BF = 495 / (1.29579 − 0.35004×log₁₀(waist+hip−neck) + 0.22100×log₁₀(height)) − 450

Getting an Accurate Measurement

  • Use a flexible, non-stretch tape measure
  • Measure the neck just below the larynx
  • Measure the waist at the narrowest point (not at the navel)
  • Measure hips (women) at the widest point
  • Keep the tape snug but not compressing the skin

How This Compares to Other Methods

The Navy method is a reasonably accurate, low-cost field estimate, but it's less precise than DEXA scans, hydrostatic weighing, or skinfold calipers performed by a trained professional. It's a good tracking tool for monitoring change over time using a consistent method.

Frequently Asked Questions

How accurate is the U.S. Navy body fat method?

Studies generally show it's within a few percentage points of more precise lab methods for most people, making it a reasonably reliable field estimate, though not as exact as DEXA scanning.

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

The formula was derived separately for each gender based on typical fat distribution patterns, and the women's version specifically includes hip circumference for accuracy.

What's a healthy body fat percentage?

This varies by age and gender, but general fitness ranges are roughly 14–24% for men and 21–31% for women — see the categories table on this page for details.

Sources