How is body fat calculated?

This calculator uses the US Navy Method. For men, it uses height, neck, and waist circumference. For women, it adds hip measurement to account for natural differences in body fat distribution.

What is a good body fat percentage?

It varies by gender and age. Generally, for men, 14-17% is considered 'Fitness' and 18-24% is 'Average'. For women, 21-24% is 'Fitness' and 25-31% is 'Average'.

Why do I need to measure my neck?

Neck circumference is a proxy for upper body muscle/frame size in the US Navy formula. It helps differentiate between someone who has a large waist due to fat vs. a large frame.

How accurate is this calculator?

The US Navy method is widely considered accurate within 1-3% for most people compared to hydrostatic weighing. However, dehydration, bloating, or incorrect tape placement can affect results.

Body Fat Calculator | US Navy Method Estimate

Body Composition

Calculate Your Body Fat %

BMI tells you weight, but Body Fat tells you composition. Use the **US Navy Method** to get a clearer picture of your health by measuring key circumference points.

US Navy Standard Formula
Adjusts for Gender Differences
Instant Fitness Category Classification

Male

Female

Height (cm)

Neck (cm)

Waist (cm)

Why Measure Body Fat?

Weight can be misleading. A body builder and an obese person might have the same BMI, but completely different body fat percentages.

No Calipers Needed

We use the tape measure method, which is non-invasive and easy to do at home without special equipment.

Gender Specific

Women naturally carry more essential fat. Our calculator adjusts formulas to ensure fair categorization for everyone.

True Health Metric

Tracking body fat percentage gives you a much better indication of metabolic health and fitness progress than scale weight alone.

How to Measure Correctly

Neck

Measure below the larynx (Adam’s apple). Keep tape flat and horizontal.

Waist

Men: Measure at navel level. Women: Measure at the smallest circumference (natural waist).

Hips (Women Only)

Measure at the widest part of the buttocks.

Reference Chart (Men / Women)

Essential Fat 2-5% / 10-13%
Athletes 6-13% / 14-20%
Fitness 14-17% / 21-24%
Average 18-24% / 25-31%
Obese 25%+ / 32%+

Frequently Asked Questions

Is this calculator as accurate as a DEXA scan?

No. A DEXA scan is the clinical “gold standard.” However, the US Navy Method is considered one of the most accurate estimation methods available for home use, often getting within 3-4% of DEXA results when measurements are precise.

Can I measure over clothes?

For accuracy, measurements should be taken on bare skin. Clothes add circumference and will artificially inflate your body fat percentage.