Navy Body Fat Calculator – US Navy Body Fat Percentage (cm & kg)
Use this free Navy body fat calculator to estimate your body fat percentage from a tape measure. Enter your height, neck and waist (and hips for women) in centimetres and it uses the US Navy method to show body fat, fat mass and lean mass.
Navy body fat calculator
Measure with a soft tape, then press calculate.
What is the US Navy body fat method?
The US Navy method estimates body fat percentage from tape measurements rather than scales or calipers. It was developed so service members could be assessed without special equipment. This Navy body fat calculator uses centimetres and kilograms: enter your height, neck and waist (plus hips if you are female) and it returns your body fat percentage, fat mass and lean mass.
How to measure for the Navy body fat calculator
- Neck: measure just below the larynx (Adam's apple), with the tape sloping slightly down at the front.
- Waist: men measure level with the navel. Women measure at the narrowest point, or at the navel if there is no obvious narrowing. Relax and breathe out normally.
- Hips (women): measure around the widest part of the hips and buttocks.
- Stand tall, keep the tape snug but not tight, and take each measurement twice, using the average.
The formula
For men, body fat % = 495 ÷ (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450. For women, body fat % = 495 ÷ (1.29579 − 0.35004 × log10(waist + hips − neck) + 0.22100 × log10(height)) − 450. All measures are in centimetres. Worked example: a man who is 175 cm with a 38 cm neck and 85 cm waist works out at about 17 percent body fat.
Body fat percentage categories
| Category | Men | Women |
|---|---|---|
| Essential fat | 2 to 5% | 10 to 13% |
| Athletes | 6 to 13% | 14 to 20% |
| Fitness | 14 to 17% | 21 to 24% |
| Average | 18 to 24% | 25 to 31% |
| Higher | 25% and over | 32% and over |
How accurate is it?
The Navy method is usually within about 3 to 4 percentage points of more precise scans, but it can be off for very lean or very muscular people, or if your fat sits in different places from average. It is best for tracking changes over time, using the same method each time. For a wider view, also check your BMI and waist size.
Turning the result into a plan
If you want to reduce body fat, work out a sensible deficit with the calorie deficit calculator, and keep protein high with the protein calculator to protect muscle. Browse protein powder, weight loss and protein bar options.
Frequently asked questions
How accurate is the US Navy body fat calculator?
It is typically within about 3 to 4 percentage points of more precise methods. It is best used to track changes over time with consistent measuring.
What is a healthy body fat percentage?
For men, roughly 14 to 24 percent is a typical healthy range, and for women roughly 21 to 31 percent. Athletes are often lower.
Why does the calculator ask for hips only for women?
The Navy formula for women includes hip measurement because fat is distributed differently, so it improves accuracy.
Can I use this body fat calculator for the Australian Defence Force?
It is the same method but not an official ADF assessment. Follow the official fitness and body composition requirements for any service entry.
How often should I measure my body fat?
Every two to four weeks is plenty. Measure at the same time of day, under the same conditions, and judge the trend rather than a single reading.
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General information only, not medical or dietary advice. If you have a medical condition, are pregnant or breastfeeding, or are making big changes to your diet or exercise, speak to your doctor or an accredited practising dietitian.