Body fat percentage from a tape measure, plus fat and lean mass.
Estimated body fat
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Fat mass
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Lean mass
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Healthy range for you
Where you sit
The tape method is an estimate with a margin of roughly ±3-4 percentage points against a DEXA scan, and it assumes a typical build. It is not a diagnosis. Talk to a doctor or a qualified trainer before acting on the number.
How this works
US Navy tape method, measurements in centimetres
Men: %fat = 495 ÷ (1.0324 − 0.19077·log10(waist − neck) + 0.15456·log10(height)) − 450
Women: %fat = 495 ÷ (1.29579 − 0.35004·log10(waist + hip − neck) + 0.22100·log10(height)) − 450
Category
Men
Women
Essential fat
2–5%
10–13%
Athletic
6–13%
14–20%
Fit
14–17%
21–24%
Average
18–24%
25–31%
Above average
25%+
32%+
Measure the waist at the navel and the neck just below the larynx, tape snug but not compressing.
Women need a hip measurement at the widest point; the male formula does not use it.
Body fat says more than BMI, because it separates fat from muscle — the two can disagree sharply in athletes.
Measure at the same time of day; a full stomach or bloating can shift the waist figure by a centimetre or two.
How accurate is the tape method?
Within about 3-4 percentage points of a DEXA scan for most people. It is far more useful for tracking change over time than as an absolute figure.
What is a healthy body fat percentage?
Roughly 14-24% for men and 21-31% for women. Below the essential minimum — about 5% for men, 13% for women — is unsafe.
Why is this different from my BMI?
BMI only compares weight to height and cannot tell muscle from fat. Someone muscular can have a high BMI and low body fat; someone sedentary can have a normal BMI and high body fat.
How often should I remeasure to track progress?
Every 2-4 weeks is enough to see a real trend without chasing daily noise from water retention or bloating. Measure at the same time of day and in the same conditions each time so the comparisons are fair.