📌 Overview

Estimate body fat percentage with the U.S. Navy method using simple circumference measurements. A quick, private alternative to expensive scans.

💪 Body Fat Calculator

Estimate body fat percentage with the U.S. Navy method using simple circumference measurements. A quick, private alternative to expensive scans.

Sex

Height (cm)

Waist (cm)

Neck (cm)

Hip (cm, female)

Enter measurements to estimate body fat.

🔒 All processing happens in your browser. No data is uploaded to any server.

📋 How to Use

Select your sex.
Enter height, waist and neck circumference.
For women, also enter hip circumference.
See your estimated body fat percentage.

❓ FAQ

How accurate is the Navy method?

It correlates well with more precise methods for most people, but athletes with unusual muscle distribution may see larger error. Treat it as an estimate.

Why do women enter hip circumference?

The female formula accounts for hip fat distribution, which the male formula does not need.

What units should I use?

Use centimeters for all measurements to match the formula constants.

❓ More Questions

Is the Navy method accurate?

For most people it agrees well with more precise methods, but those with unusual muscle distribution may see larger error - treat it as a reference only.

Why do women enter hip circumference?

The female formula accounts for fat distribution around the hips; the male formula does not need it.

💡 Use Cases

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Fitness

Track fat loss progress.

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Home Check

Estimate without a scan.

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Goals

Set realistic targets.

🔗 Related Tools

📖 Deep Dive: Body Fat Calculator

Why estimate body fat

People with the same weight can have very different body fat; body fat percent reflects body composition better than BMI. The circumference method needs no equipment, ideal for home self-testing.

How it works

The Navy method plugs height, waist, and neck (plus hip for women) into an empirical formula to estimate body fat percentage; the formula uses separate constants for men and women.

A quick example

Male, height 175cm, waist 85cm, neck 38cm - the formula gives about 20% body fat, within the healthy range.