How body fat calculator works
Body fat percentage is the fraction of your body mass that is fat, as opposed to muscle, bone, and water. It is a better health indicator than weight or BMI alone because it distinguishes fat from lean mass. The US Navy method estimates it from a few circumference measurements.
This calculator uses the US Navy circumference formulas, which take height, neck, and waist for men, and add a hip measurement for women. The formulas use logarithms of the difference between waist and neck (and hip for women) relative to height, and have been shown to correlate well with more precise methods like underwater weighing.
Enter your gender, height, neck, and waist (and hip if female) in centimetres. The tool returns the estimated body fat percentage and a fitness category — Essential fat, Athletic, Fitness, Average, or Obese — based on standard ranges. It is an estimate, not a clinical measurement; for precision use DEXA or hydrostatic weighing.