Body composition calculator
Body fat calculator
Estimate your body-fat percentage with a tape measure — no calipers, no scales. The US Navy method. Free, instant, no sign-up.
Set a target and get a plan to reach it — the coach remembers it and adapts each week.
What is the Navy body-fat method?
The US Navy circumference method estimates body-fat percentage from a few tape measurements — neck, waist, and (for women) hips — plus your height. No calipers, no scales, no lab. It's the most accessible estimate you can do at home in two minutes.
How this calculator works
It fits a logarithmic regression to your measurements (all in cm, using base-10 logs). For men: 495 / (1.0324 − 0.19077·log₁₀(waist − neck) + 0.15456·log₁₀(height)) − 450. For women, hip circumference is added into the waist term. Measure the waist at the navel and the neck just below the larynx for the most consistent reading.
How to use the number
Treat this as a population-fit estimate, not a DEXA scan — it's most valuable for tracking a trend over weeks, not as a single absolute number. Measure under the same conditions each time. Want a cut or recomp plan built around your number and re-checked as you go? That's what the coach is for.