Free & private

Body Fat Calculator

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

Your measurements

Use a flexible tape measure for best results.

cm
cm
cm
%Your result will appear hereAdd your measurements, then select calculate to see your estimated body fat %.
Estimated body fat
0.0%
EssentialAthleticAverageObese

The US Navy method is a widely used estimate, not as precise as DEXA scans, calipers or hydrostatic weighing. Results can vary with measurement technique.

How to use the body fat calculator

This free calculator works with metric and imperial units. Select your sex, choose your units, and enter your height, neck and waist measurements (plus hip for women), then select calculate. Everything runs locally in your browser, so nothing is uploaded or stored by this tool.

1. Select sex & units

Choose male or female, then metric or imperial measurements.

2. Take measurements

Measure neck, waist and (for women) hip with a soft tape measure.

3. Review your result

See your estimated body fat % and category instantly.

Understanding your body fat result

The US Navy circumference method estimates body fat percentage from a handful of tape measurements rather than skinfold calipers or scanning equipment, making it a convenient at-home estimate that correlates reasonably well with more precise methods for most adults.

Men's formula

BF% = 495 ÷ (1.0324 − 0.19077×log₁₀(waist−neck) + 0.15456×log₁₀(height)) − 450, in centimeters.

Women's formula

BF% = 495 ÷ (1.29579 − 0.35004×log₁₀(waist+hip−neck) + 0.22100×log₁₀(height)) − 450, in centimeters.

Measuring tips

Measure neck below the larynx, waist at the navel, and hip at its widest point, with the tape snug but not compressing the skin.

How is body fat percentage calculated here?

This calculator uses the US Navy circumference method, which estimates body fat from neck and waist measurements (plus hip for women) and height.

Why does the formula need different measurements for men and women?

Body fat tends to distribute differently between men and women, so the Navy method adds a hip measurement and uses different coefficients for women.

How accurate is the Navy method?

It is a reasonably useful estimate for most adults, but it is less precise than methods like DEXA scans, skinfold calipers or hydrostatic weighing.

Where do I measure my waist and neck?

Measure the neck just below the larynx, the waist at the navel (or narrowest point), and for women the hip at its widest point, keeping the tape snug but not tight.

Try another free calculator: BMI Calculator, VO2 Max Estimator, or Calorie Calculator. Browse all online tools.