Body Fat Calculator

Estimate your body fat percentage using the US Navy method. See your fat mass, lean mass and category.

Gender

Male Female

Height (cm) Weight (kg) Waist circumference at navel (cm) Neck circumference (cm)

Hip circumference (cm) - Women only

What is Body Fat Percentage?

Body fat percentage is the proportion of your total body weight that is made up of fat tissue. It is a more meaningful measure of fitness than body weight alone, because two people of the same weight can have very different amounts of fat and muscle. Knowing your body fat percentage helps you understand your overall health, set realistic fitness goals, and track progress over time.

How to Use This Calculator

Select your gender, then enter your height, weight, waist circumference (measured at the navel), and neck circumference. Women also need to enter their hip circumference. Click "Calculate Body Fat" to see your estimated body fat percentage, fat mass, lean mass and fitness category. All measurements should be taken on bare skin with a flexible tape measure.

Formula (US Navy Method)

The US Navy body fat formula uses circumference measurements and height:

Men: Body Fat % = 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76

Women: Body Fat % = 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387

All measurements are in centimetres. This method has been validated against hydrostatic weighing and is considered reasonably accurate for most people.

Body Fat Categories

Men: Essential Fat: 2-5%, Athletes: 6-13%, Fitness: 14-17%, Average: 18-24%, Obese: 25%+

Women: Essential Fat: 10-13%, Athletes: 14-20%, Fitness: 21-24%, Average: 25-31%, Obese: 32%+

Frequently Asked Questions

How accurate is the US Navy body fat method?

The US Navy method is generally accurate within 1-3% for most people when measurements are taken correctly. It is less accurate for very muscular individuals or those with unusual body proportions. For clinical precision, DEXA scans or hydrostatic weighing are recommended.

How should I measure my waist and neck?

Measure your waist horizontally at the level of your navel. Measure your neck just below the larynx (Adam's apple), sloping slightly downward at the front. Women should measure hips at the widest point. Use a flexible tape measure snug against the skin without compressing it.

What is a healthy body fat percentage?

For men, 14-24% is considered average and healthy. For women, 21-31% is the average healthy range. Athletes typically have lower body fat percentages. Going below the essential fat level (2-5% for men, 10-13% for women) can be dangerous to health.