HEALTH · BODY FAT
Body Fat Calculator
Estimate your body fat percentage with the US Navy circumference method from neck, waist, hip, and height measurements, in metric or imperial units.
Body Fat (US Navy method)
16.2%
Fitness
CategoryFitness
MethodUS Navy circumference
About This Calculator
This calculator estimates body fat percentage using the US Navy circumference method — a tape-measure technique that needs no special equipment. It is an estimate; DEXA and hydrostatic weighing remain the clinical gold standards.
How It Works
Measure your neck, waist, and (for women) hip circumference, plus your height. The calculator applies the US Navy formula, which uses the difference between waist and neck (and hip for women) relative to height. Switch between metric and imperial units freely.
The Formula
Men: %BF = 86.010·log₁₀(waist − neck) − 70.041·log₁₀(height) + 36.76
- waist
- waist circumference (inches)
- neck
- neck circumference (inches)
- height
- height (inches)
Frequently Asked Questions
- How accurate is the US Navy body fat method?
- It is a reasonable estimate for most people, typically within a few percentage points of clinical measurement. Accuracy depends on consistent, snug (not tight) tape placement. DEXA scans and hydrostatic weighing are more precise.
- Where do I measure my waist and neck?
- Measure the neck just below the larynx, sloping slightly downward to the front. Measure the waist horizontally at the navel for men, and at the narrowest point for women. Women also measure the hip at its widest point.
- Why does the female formula need a hip measurement?
- The female US Navy formula includes hip circumference because women's body fat distribution differs from men's. Without it, the estimate would be inaccurate, so the hip field is required when female is selected.