How to use the body fat calculator
Measure your neck just below the larynx, and your waist at the navel for men or at the narrowest point for women. Women also measure the hips at their widest point. Keep the tape level and snug without pressing into the skin, and take each measurement twice.
Add your weight if you would like to see how many kilograms or pounds of you are fat and how many are lean tissue.
The formula
The US Navy method, with all measurements in centimetres:
- Men:
495 ÷ (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450 - Women:
495 ÷ (1.29579 − 0.35004 × log10(waist + hips − neck) + 0.22100 × log10(height)) − 450
Worked example
A man who is 178 cm tall with a 38 cm neck and a 90 cm waist has a waist minus neck figure of 52 cm. Putting that into the formula gives a body fat estimate of about 20.1%.
This calculator gives a general estimate for adults. It is not medical advice. Talk to a doctor or other qualified health professional about your own situation.
Common questions
How accurate is the tape-measure method?
It is usually within three or four percentage points of laboratory methods such as a DEXA scan. It is best used to track change over time.
What is a healthy body fat percentage?
The American Council on Exercise describes 14% to 24% for men and 21% to 31% for women as the fitness to average range.
Why do women have a different formula?
Women naturally carry more essential fat and store it differently, so the hips are included to improve the estimate.