Body Fat Calculator
Estimate body fat percentage and lean mass using the US Navy method. Enter height, neck, waist, and hip measurements.
Body Fat %
Fat Mass
Lean Body Mass
Category
Athlete
6–13%
Results are estimates only and not a substitute for medical or nutritional advice.
How to Use
Select sex and enter height
Choose your sex and enter your height in centimeters.
Measure and enter circumferences
Enter your neck and waist (at navel level) circumferences. Women should also enter hip circumference at the widest point. Use a flexible tape measure held horizontally.
View your results
Body fat percentage, fat mass, and lean body mass are calculated instantly. A category rating based on ACE (American Council on Exercise) standards is also shown.
FAQ
The US Navy body fat formula estimates body fat percentage from height, neck, and waist measurements (plus hip for women). It is widely used because it requires only a tape measure and is more accurate than BMI for most people.
Measure horizontally at navel level while relaxed and exhaling normally. Do not suck in your stomach or measure while breathing in, as this will give an inaccurate reading.
According to ACE standards, fitness range is 14–17% for men and 21–24% for women. Average is 18–24% for men and 25–31% for women. Athletes typically fall below these ranges.
The US Navy method is an estimate that may differ by a few percentage points from precise methods like DEXA scans or hydrostatic weighing. Factors like body shape and muscle mass can affect accuracy. Use it as a general guideline.
Lean body mass is your total body weight minus fat mass. It includes muscle, bone, organs, and body fluids. When losing weight, maintaining LBM while reducing fat is considered the healthiest approach.