Body Fat Percentage Calculator
Uses the U.S. Navy tape-measure method — a well-known estimate that needs only a measuring tape, no calipers.
How accurate this is
The Navy method is a circumference-based estimate, generally accurate to within a few percentage points for most body types — good for tracking trends over time, not a substitute for DEXA scans or clinical measurement.
About the Body Fat Percentage Calculator
The Body Fat Calculator estimates body fat percentage using the U.S. Navy tape-measure method, which needs only height and a few circumference measurements. It is a convenient way to track change over time without special equipment, although it is less precise than clinical methods such as DEXA scans.
The method uses the difference between waist and neck circumference (and hip for women) relative to height in a logarithmic equation. Because it relies on measurements taken with a tape, small errors in placement can shift the result by several percentage points. Use it to watch the trend rather than to chase an exact value.
How to use it
- Select your sex and enter your height.
- Measure your neck just below the larynx and your waist at the navel (and hips at the widest point if prompted).
- Enter the measurements in the same unit as the tool asks.
- Read the estimated body fat percentage and category.
Tips and good to know
- Measure at the same time of day, standing relaxed, with the tape snug but not compressing the skin.
- Take each measurement twice and use the average.
- Categories differ by age and sex; athletes and non-athletes have different typical ranges.
Frequently asked questions
How accurate is it?
Studies of the method show a typical error of several percentage points, so use it for trends.
Why does it ask for hips only sometimes?
The equation for women includes hip circumference; the one for men does not.
Is a low number always better?
No. Essential fat is necessary for health.