Body Fat Calculator
Body fat % from tape measurements (US Navy method).
About this tool
Body Fat Calculator estimates your body fat percentage using the US Navy tape-measure method, which needs only a measuring tape. Add your weight to see fat mass and lean mass. It works in centimetres or inches.
How to use Body Fat Calculator
- Choose units and sex.
- Measure and enter height, neck and waist (plus hip for women).
- Read your body fat percentage and category.
Questions people ask
What is the US Navy body fat formula?
In centimetres, 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.
Where should I measure?
Neck just below the larynx (Adam's apple). Waist at the navel for men and at the narrowest point for women. Hips at the widest point of the buttocks. Keep the tape level and snug without pressing into the skin, and measure in the morning.
How accurate is it?
Studies put the tape method within about 3 to 4 percentage points of lab methods such as DEXA for most people. It is less reliable for very lean or very muscular builds. Use it to track change over time with the same tape and the same spots.