Body Fat Calculator
Body fat percentage is the share of your total weight that is fat. This calculator uses the US Navy circumference method — based on your height, neck and waist, plus hip for women — to estimate your body fat percentage without special equipment, just a tape measure.
Body Fat Calculator
The US Navy body fat method
This method estimates body fat from body circumferences and height. For men it uses the neck and waist; for women it also includes the hip. The result is your body fat percentage, and if you enter your weight it also splits your weight into fat mass and lean mass.
Typical ranges
Healthy body fat is roughly 10-20% for men and 18-28% for women. Very low levels can be unhealthy, since some fat is essential for the body to work.
Frequently asked questions
How is body fat calculated with the US Navy method?
It uses tape measurements of your neck, waist (and hip for women) together with your height in a formula based on logarithms, with no scale or callipers needed.
How accurate is the US Navy body fat method?
For most people it is within about 3-4% of a precise measurement, which is good for tracking changes over time, though it is still an estimate.
What is a healthy body fat percentage?
For men a typical healthy range is about 10-20%, and for women about 18-28%, with athletes often lower. Ranges vary with age.
Where exactly do I measure?
Measure your neck below the larynx, your waist at the navel, and for women the hip at its widest point, keeping the tape snug and level.
Why are the formulas different for men and women?
Women carry more essential fat and distribute it differently, so the formula adds the hip measurement and uses different constants.