About the Body Fat Calculator
Estimate body fat percentage with nothing more than a tape measure. This calculator uses the U.S. Navy formula based on height, neck and waist (plus hips for women) and shows fat mass, lean mass and your fitness category.
How to use it
- Choose sex and units.
- Measure height, neck (below the larynx) and waist (at the navel for men, narrowest point for women).
- Women: also measure the widest part of the hips.
Formula & method
Men: 495 ÷ (1.0324 − 0.19077·log10(waist − neck) + 0.15456·log10(height)) − 450
Women: 495 ÷ (1.29579 − 0.35004·log10(waist + hip − neck) + 0.221·log10(height)) − 450Frequently asked questions
How accurate is the Navy method?
It is typically within about 3–4% of lab methods such as DEXA, provided measurements are taken carefully and consistently.
Results are estimates for general information only and are not financial, tax, legal or medical advice. Please confirm important decisions with a qualified professional.