Body Fat Percentage Calculator (US Navy Method)
Estimate your body fat percentage using the US Navy tape-measure method based on waist, neck and height measurements.
Your results
This is a circumference-based estimate; scales, DEXA or skinfold measurements may differ.
Calculation breakdown
- Men
- %BF = 495 / (1.0324 − 0.19077×log10(waist−neck) + 0.15456×log10(height)) − 450
- Women
- %BF = 495 / (1.29579 − 0.35004×log10(waist+hip−neck) + 0.22100×log10(height)) − 450
Worked example
A man 175 cm tall with an 85 cm waist and 38 cm neck has an estimated body fat percentage of around 16%, using the US Navy circumference method.
Assumptions
- All measurements should be in centimetres for the formula to work correctly.
- This method can be less accurate for very lean or very muscular individuals.
How this calculator works
This calculator estimates body fat percentage using the US Navy circumference method, which uses waist, neck and (for women) hip measurements alongside height. It is a widely used field method that avoids the need for specialised equipment like skinfold calipers or DEXA scans, though it remains an estimate rather than a precise measurement.
Frequently asked questions
How accurate is the US Navy method?
It is a reasonable field estimate for most people but can be less accurate for very lean or very muscular individuals.
What measurements do I need?
You need waist, neck and height for men, plus hip circumference for women, all measured in centimetres.
Where should I measure my waist?
Measure at the narrowest point of your torso, typically level with your navel, without pulling the tape tight.
Results are estimates only and are not financial, tax, legal or credit advice.