TOOLEstimate your body fat with a tape measure
This calculator uses the US Navy circumference method — the same approach the military uses for a quick body-composition check. It reads your body fat from the size of your neck and waist (and hips for women) relative to your height, so all you need is a soft tape measure. Enter your weight too and it also splits your body into fat mass and lean mass.
Body fat percentage categories
Women: 10–13% essential · 14–20% athlete · 21–24% fitness · 25–31% average · 32%+ obese
Track the trend rather than chasing an exact number. Pair this with the BMI calculator and TDEE calculator to plan a fat-loss or muscle-gain phase.
This is a general estimate for educational purposes only and is not medical advice or a diagnosis. Circumference formulas are approximations. Consult a qualified healthcare professional before making changes to diet or exercise.
Frequently asked questions
How does the US Navy body fat method work?
It estimates body fat from the circumference of your neck and waist (plus hips for women) relative to your height. These measurements correlate with body fat, so the formula returns a percentage without needing calipers or a scan.
How accurate is this body fat calculator?
The Navy method is typically within about 3 to 4 percent of a DEXA scan for most people, which is good for a free tape-measure estimate. Accuracy depends on measuring carefully at the right spots. Use it to track trends over time rather than as an exact figure.
Where do I measure my waist and neck?
Measure your neck just below the larynx, your waist at the navel for men and at the narrowest point for women, and hips at the widest point for women. Keep the tape snug and level, and measure without holding your breath.