Body Fat Calculator
Estimate your body fat percentage with the U.S. Navy tape-measure method. It needs only a few measurements and gives a body-composition signal that BMI cannot.
How the body fat calculator works
The U.S. Navy method estimates body fat from the circumference of your neck and waist (and hips for women) relative to your height. Measured carefully, it lands surprisingly close to more expensive methods.
How to measure
Use a flexible tape, snug but not compressing the skin. Measure your neck just below the larynx, your waist at the navel (at the narrowest point for women), and, for women, your hips at the widest point. Measure on bare skin and breathe normally.
Body fat categories
Healthy ranges differ by sex. For women, roughly: 10 to 13 percent is essential fat, 14 to 20 athletic, 21 to 24 fitness, 25 to 31 average, and 32 percent or more is high. For men: 2 to 5 essential, 6 to 13 athletic, 14 to 17 fitness, 18 to 24 average, and 25 percent or more is high. These ranges come from the American Council on Exercise.
Frequently asked questions
How is body fat percentage calculated here?
This calculator uses the U.S. Navy circumference method, which estimates body fat from your height and a few tape measurements: neck and waist for men, plus hips for women. It is a formula, not a body scan, so treat the result as a solid estimate.
How accurate is the Navy body fat method?
Measured carefully, it is typically within a few percentage points of advanced methods like DEXA. Sloppy or compressed measurements are the main source of error, so measure on bare skin with the tape snug but not tight, and measure twice.
What is a healthy body fat percentage?
It depends on sex. For women, around 21 to 24 percent is fitness level and 25 to 31 average; for men, about 14 to 17 percent is fitness and 18 to 24 average. Some essential fat is required for health, and extremely low levels carry their own risks.
Why is this different from my smart scale?
Different methods use different models. Bioimpedance scales send a small current and are sensitive to hydration, food, and time of day, while the Navy method uses measurements. Neither is a clinical scan, so expect some difference. Track the trend over time, not one reading.
Is body fat better than BMI?
They answer different questions. BMI uses only height and weight, so it can misjudge muscular people; body fat percentage estimates composition directly. Body fat is more informative for fitness, while BMI is quicker. Using both gives a fuller picture than either alone.