Body Fat Calculator
Free online body fat calculator using the US Navy method. Estimate your body fat percentage from a few tape measurements — metric or imperial.
About the Body Fat Calculator
Our free online body fat calculator estimates your body fat percentage using the trusted US Navy circumference method. Enter your height and a few simple tape measurements — neck and waist for men, plus hip for women — and it calculates your body fat percentage along with a fitness category. Add your weight and it also shows your fat mass and lean body mass. It supports metric and imperial units and runs entirely in your browser with no signup, so your measurements stay private. It is a quick, no-equipment way to track changes over time.
Features
- US Navy circumference (tape) method
- Body fat percentage with a fitness category
- Optional fat mass and lean body mass
- Metric (cm/kg) and imperial (in/lb) units
- 100% free, no signup — runs in your browser
- Uses height and tape measurements; no calipers required
How to use this tool
The Body Fat Calculator works right in your browser — no signup, no installation. Follow these steps:
- Choose your units and gender.
- Enter your height, neck, and waist measurements (and hip for women).
- Optionally add your weight to see fat mass and lean mass.
- Read your estimated body fat percentage and category.
Frequently asked questions
How does the US Navy body fat method work?
It estimates body fat from body circumference measurements — height and neck and waist (plus hip for women) — using a validated formula. It is not as precise as a DEXA scan but is free, repeatable, and good for tracking trends.
Where do I measure neck, waist, and hip?
Measure the neck just below the larynx, the waist at the navel for men and at the narrowest point for women, and the hip at the widest point. Keep the tape level and snug but not tight for consistent results.
What is a healthy body fat percentage?
General ranges are roughly 14–24% for men and 21–31% for women as average/healthy, with athletes lower. Essential fat is about 2–5% for men and 10–13% for women. The tool labels your result with a category.
Using the results
Use the Body Fat Calculator to calculate from the values you enter. Check the displayed units, rounding and supported inputs when interpreting the result.