📏 Body Fat Percentage Calculator
All you need is a tape measure. Enter your height and the circumference of your neck and waist (and hips for women) to estimate your body fat percentage using the US Navy formula.
How the Body Fat Percentage Calculator works
The US Navy method estimates body fat from circumference measurements using a log-based formula developed from body-density studies. It is usually within a few percent of lab methods for most adults.
Step-by-step calculation
- 1Measure height, neck and waist (and hips for women).
- 2Apply the US Navy formula.
- 3Compare with fitness categories.
Worked example
A man 178 cm tall with a 38 cm neck and 86 cm waist: about 17.2% body fat.
Body Fat Percentage Calculator examples
| Waist (cm) | Estimated body fat |
|---|---|
| 76 | 8.8% |
| 81 | 13.2% |
| 86 | 17.2% |
| 91 | 20.9% |
| 96 | 24.2% |
| 102 | 28% |
Other inputs kept at the calculator's default values. Results calculated by this calculator.
Why use a Body Fat Percentage Calculator?
Estimate body fat without special equipment.
Important factors that can affect your results
- Measuring tape position.
- Time of day and hydration.
- Formulas are estimates (±3–4%).
Frequently asked questions
Where do I measure my waist?
Men measure at the navel; women at the narrowest point. Keep the tape level and do not pull it tight.
Is this as accurate as a DEXA scan?
No. It is a good estimate for tracking progress, not a medical measurement.
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Last reviewed November 2026 · How we build and check our tools · Report a problem