Body Fat Calculator
Estimate your body fat percentage using circumference measurements — height, neck, waist and (for women) hip — with the widely used U.S. Navy method. Understand the healthy ranges for your sex.
What this means
Body fat percentage is the share of your weight that is fat. The Navy method predicts it from circumference measurements that correlate with fat distribution, giving a good approximation without special equipment.
How we calculate it
Formula
Men: 495 ÷ (1.0324 − 0.19077·log₁₀(waist − neck) + 0.15456·log₁₀(height)) − 450. Women use waist + hip − neck and different constants.Worked example
A man, 180 cm tall, 40 cm neck, 90 cm waist:
- 1waist − neck = 50 cm
- 2Plug measurements into the Navy formula
- 3Read the estimated body fat %
Important assumptions
- Circumference estimates are approximate; DEXA or hydrostatic weighing are far more precise.
Frequently asked questions
What is a healthy body fat percentage?
For men, 14–24% is typically healthy; for women, 21–31%. Athletes usually sit lower, and essential fat floors are about 5% (men) and 12% (women).
How do I measure correctly?
Measure at the navel for waist, below the larynx for neck, and the widest point for hips, keeping the tape snug but not tight.
Guide
BMI Calculator Guide: How to Read Your Body Mass Index
BMI is a quick screening number, not a diagnosis. Here is how to use it correctly and what to look at next.
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