Body fat calculator

Estimate your body fat percentage with the US Navy tape-measure method — no calipers or scales needed.

Units
The US Navy method uses a different equation for each, and the female equation also needs a hip measurement. Why we ask.
Your standing height.
Around the narrowest point, just below the larynx.
At the navel for men, at the narrowest point for women. Relaxed — not pulled in.
Estimated body fat —

Category: —

Choose a sex assigned at birth above to see your estimate.

Body fat categories

ACE category ranges for your selected sex. Your estimate's band is highlighted.
Category Body fat range
Essential fat —
Athletes —
Fitness —
Average —
Obese —

How accurate is this?

The US Navy method typically lands within about 3–4% of a DEXA scan, but a tape measure is sensitive to where and how tightly you measure. Measure the same way each time and watch the trend over weeks — a single number matters far less than the direction it moves.

How this is calculated

The US Navy method estimates body fat from a log-scaled ratio of body circumferences to height. Each sex has its own equation.

Male: BF% = 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76

Female: BF% = 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387

The equations work in inches; metric measurements are converted internally. The result is rounded to one decimal place.

Estimates only. Not medical advice. Talk to a clinician for personal guidance.