How accurate is the US Navy Body Fat Calculator?

The US Navy tape measure method provides an estimate typically within 3-4% of DEXA scans and hydrostatic weighing when measurements are taken accurately.

What is a healthy body fat percentage?

For men, essential fat is 2-5%, athletes 6-13%, fitness 14-17%, acceptable 18-24%. For women, essential fat is 10-13%, athletes 14-20%, fitness 21-24%, acceptable 25-31%.

Body Fat Percentage Calculator

US Navy Circumference Method for Men & Women

Body Circumferences

Gender

Male

Female

Weight (kg)

Height (cm)

Neck Circumference (cm) Measure at narrowest point below Adam's apple

Waist Circumference (cm) Measure at navel level (relaxed breath)

Body Composition Analysis

Body Fat

16.4%

Fitness

Lean Mass

62.7 kg

Muscle, Bone & Water

Fat Mass

12.3 kg

Total Adipose Fat

Understanding Body Fat Categories (ACE Standards)

The American Council on Exercise (ACE) defines the following body fat ranges:

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

Frequently Asked Questions

How do I take accurate measurements?

Use a non-stretches fiberglass or cloth tape measure. Keep the tape level and snug against the skin without compressing the underlying soft tissue. Measure first thing in the morning before eating.

Why do women naturally have a higher body fat percentage?

Women carry higher essential body fat due to biological and hormonal requirements, including reproductive physiology, breast tissue, and estrogenic fat distribution.

How to Use the Body Fat Calculator

Select your biological Gender (Male or Female) as body fat algorithms differ between genders.
Enter your current Age and Weight (kg or lbs).
Input your exact Height in centimeters or feet/inches.
Measure and input your Neck and Waist circumference (and Hip circumference for females).
Click Calculate Body Fat to instantly see your body fat percentage, fat mass, and lean mass.

Body Fat Formula (US Navy Method)

The US Navy body fat formula estimates body density using circumference measurements and logarithmic height scaling:

Men: Body Fat % = 495 / (1.0324 - 0.19077 × log10(waist - neck) + 0.15456 × log10(height)) - 450

Women: Body Fat % = 495 / (1.29579 - 0.35004 × log10(waist + hip - neck) + 0.22100 × log10(height)) - 450

All circumference measurements in the formula are evaluated in centimeters.

Practical Step-by-Step Example

Consider an adult male with the following measurements:

Height: 178 cm | Weight: 80 kg
Neck Circumference: 40 cm | Waist Circumference: 86 cm
Computation: (Waist - Neck) = 46 cm. Applying the US Navy logarithmic equation yields approximately 17.2% Body Fat.
Result Breakdown: Fat Mass = 13.8 kg (80 × 0.172), Lean Body Mass = 66.2 kg.

Body Fat Percentage Calculator

Body Circumferences

Body Composition Analysis

16.4%

62.7 kg

12.3 kg

Understanding Body Fat Categories (ACE Standards)

Frequently Asked Questions

How to Use the Body Fat Calculator

Body Fat Formula (US Navy Method)

Practical Step-by-Step Example

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