Enter your sex, height, and neck / waist (and hip, for women) measurements - the estimate updates as you type. Pick metric (cm) or imperial (in) units first, then measure with a soft tape at the narrowest point of the neck and waist for the most consistent reading. The tool computes the U.S. Navy circumference-method estimate and a fitness category entirely in your browser - nothing is uploaded.
Body Fat Percentage Calculator Online
Estimate body fat percentage from a few tape-measure numbers using the U.S. Navy circumference method: height, neck, and waist for men; height, neck, waist, and hip for women.
Switch between metric (cm) and imperial (in) units at any time; the result and its fitness category (essential fat / athletic / fitness / average / above average) update as you type.
The calculation runs locally in the browser - no upload and no account. It is an estimate, not a medical measurement - a DEXA scan, bioelectrical-impedance scale, or skinfold calipers will be more precise.
Frequently Asked Questions
What does Body Fat Percentage Calculator Online do?
It estimates your body fat percentage from height, neck, and waist measurements (plus hip for women) using the U.S. Navy circumference method, and shows a fitness category alongside the number.
How accurate is the U.S. Navy circumference method?
It is a widely used estimate, typically within a few percentage points of more precise methods like DEXA scans or skinfold calipers - close enough to track trends over time, but not a medical measurement.
Do I need to sign up or upload anything?
No. Every calculation runs locally in your browser; no account, no upload, and your measurements never leave the page.