Navy Body Fat Calculator
Body fat percentage from tape measurements.
Enter your values
Choose one of: Male, Female.
Enter the neck in cm.
Enter the waist in cm.
Enter the hip (women only) in cm.
Enter the height in cm.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Estimated body fat
- 16.4%
- Lean mass share
- 83.6%
Quick answer
The US Navy circumference method estimates body fat from a log-based formula using neck, waist and hip measurements.
Men: %BF = 495/(1.0324-0.19077log10(waist-neck)+0.15456log10(height))-450
At a glance
| What it does | Body fat percentage from tape measurements. |
|---|---|
| Category | Health |
| Inputs needed | Sex, Neck, Waist, Hip (women only), Height |
| Main output | Estimated body fat |
| Formula | Men: %BF = 495/(1.0324-0.19077log10(waist-neck)+0.15456log10(height))-450 |
| Cost | Free — no sign-up, no download |
How to use the Navy Body Fat Calculator
- 1Measure neck, waist, and for women, hips, in centimetres.
- 2Enter your height in the same units.
- 3This is an estimate with roughly 3-4% error versus DEXA — do not use it for medical decisions.
Inputs explained
- Sex
- Choose one of: Male, Female.
- Neck(cm)
- Enter the neck in cm.
- Waist(cm)
- Enter the waist in cm.
- Hip (women only)(cm)
- Enter the hip (women only) in cm.
- Height(cm)
- Enter the height in cm.
Worked example
Using the values the calculator loads with:
Inputs
- SexMale
- Neck38 cm
- Waist85 cm
- Hip (women only)95 cm
- Height178 cm
Results
- Estimated body fat16.4%
- Lean mass share83.6%
Frequently asked questions
How accurate is the tape method?
It's a convenient field method, accurate to within a few percent for most body types.
Where do I measure waist?
At the narrowest point, or at the navel if there is no natural narrowing.
What do I need to enter into the Navy Body Fat Calculator?
Just 5 values: sex, neck, waist, hip (women only), height. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Navy Body Fat Calculator work out the answer?
The US Navy circumference method estimates body fat from a log-based formula using neck, waist and hip measurements. It applies the formula Men: %BF = 495/(1.0324-0.19077log10(waist-neck)+0.15456log10(height))-450 and shows the working so you can check each step by hand.
Is the Navy Body Fat Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.