About this calculator
The U.S. Navy method estimates body fat from height and circumferences. For men: 495 ÷ (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450. For women, hips are added to the waist and different constants are used. All measurements are in centimetres.
Worked example
A man 175 cm tall with a 38 cm neck and an 85 cm waist comes out at about 16.9% body fat with the US Navy method.
How to use the body fat calculator
- Choose the sex.
- Enter the height.
- Enter the neck.
- Enter the waist (at the navel).
- Read the result — it updates as you type.
Frequently asked questions
Where should I measure my waist?
Around the navel, relaxed, without pulling the tape tight.
How accurate is it?
It is a reasonable estimate, typically within a few percentage points of lab methods.