Body fat calculator
Estimate your body fat percentage with just a tape measure and see which range you fall into.
Body fat calculator: what it is and how it works
Body fat percentage tells you how much of your weight is fat. It is more informative than BMI because it distinguishes fat from muscle. Laboratory methods are very accurate, but the US Navy method lets you estimate it at home with a simple tape measure.
For men it uses height, neck and waist circumference; for women, hip circumference as well. Measure on bare skin, keeping the tape level and snug but not tight. As a guide, for men 14–17 % is “fitness” and 18–24 % average; for women, 21–24 % and 25–31 % respectively.
How to use it
- Choose your sex and enter your height.
- Measure your neck, waist and, for women, hips with a tape.
- See your body fat and, if you add your weight, your fat and lean mass.
Men: body fat % = 495 ÷ (1.0324 − 0.19077·log(waist − neck) + 0.15456·log(height)) − 450Worked example
A 178 cm man with a 38 cm neck and 85 cm waist has about 16.4 % body fat (“fitness”). A 165 cm woman measuring 33, 75 and 95 cm has 26.9 %, average.
Frequently asked questions
What is a healthy body fat percentage?
Roughly 10–20 % for men and 18–28 % for women, depending on age.
Is the tape measure method reliable?
It has an error of about 3–4 points, similar to home bioimpedance scales. It is useful for tracking progress.
How do I measure my waist correctly?
Standing relaxed, at the end of a normal breath out. Men at the navel; women at the narrowest point.
Why do women have more body fat?
Essential fat is higher in women for hormonal and reproductive reasons, so their ranges are higher.