Body Fat Calculator
Estimate your body fat percentage using the U.S. Navy circumference method. Enter a few measurements to get a quick, formula-based estimate.
Estimate your body fat percentage using the U.S. Navy circumference method. Enter a few measurements to get a quick, formula-based estimate.
The U.S. Navy method estimates body fat percentage from simple tape measurements rather than specialized equipment. For men it uses height, neck, and waist measurements; for women it adds the hip measurement. These values are entered into a validated formula that approximates body fat percentage. It is not as precise as laboratory methods like DEXA scans, but it is free, repeatable at home, and good enough to track changes over time when you measure consistently.
Healthy ranges differ by sex because women naturally carry more essential fat. As a general guide, many references consider roughly 10–20% healthy for men and about 18–28% for women, with athletes often lower and these bands shifting with age. Body fat percentage is a better indicator of body composition than weight alone, but the exact healthy range depends on individual factors, so use these figures as broad orientation rather than strict targets.
Weight alone cannot distinguish muscle from fat, so two people of the same weight can have very different body compositions and health profiles. Tracking body fat percentage shows whether changes in weight come from losing fat, gaining muscle, or both. This is especially useful when exercising, since you may build muscle and lose fat with little change on the scale — progress that body fat measurement reveals but weight hides.
Measure at the same time of day under similar conditions, use a flexible but non-stretchy tape, and keep the tape snug without compressing the skin. Take the waist at the navel, the neck just below the larynx, and the hips at the widest point. Recording two measurements and averaging them reduces error. Consistency matters more than perfection — the same small technique each time makes your trend reliable even if any single reading is slightly off.
No. Methods like DEXA, hydrostatic weighing, and air-displacement scans are more precise because they directly assess body composition. The Navy circumference method relies on the statistical relationship between measurements and fat, so individual results can differ from a lab reading by a few percentage points. Its strength is convenience and consistency, making it a practical way to monitor direction of change between occasional, more accurate assessments.