What is a healthy body fat percentage?

Men: 10-20% is fit, 20-25% average. Women: 18-28% is fit, 25-31% average. Athletes may be lower. Essential fat: Men 2-5%, Women 10-13%.

How accurate is this method?

The US Navy method is ~3-4% accurate compared to DEXA scan. For precise measurement, use DEXA scan or hydrostatic weighing. This calculator provides a good estimate.

What measurements do I need?

You need height, waist (at navel), and neck (below Adam's apple). Women also need hip measurement (widest point). Use a soft measuring tape.

How often should I measure body fat?

Measure monthly for tracking progress. Daily measurements can vary due to hydration and other factors. Focus on trends over time, not daily fluctuations.

What affects body fat percentage?

Body fat percentage is affected by diet, exercise, age, genetics, and hydration. Muscle mass also affects the calculation, as the US Navy method doesn't directly measure body composition.

Can I use this for weight loss tracking?

Yes, tracking body fat percentage monthly can be more meaningful than just tracking weight, as it shows changes in body composition. However, use it as a guide, not the only metric.

Body Fat Calculator

Estimate your body fat percentage using the US Navy method. Enter your gender, height, waist, neck, and hip measurements (for women) in metric or imperial units to automatically calculate body fat percentage and category.

Calculator (US Navy Method)

Result

Body Fat: 0.0%
Category: -

Formula & Guide

Formula

M

Men

BF% = 495 / (1.0324 - 0.19077×log(waist-neck) + 0.15456×log(height)) - 450

Uses waist, neck, and height measurements (cm or inches converted to cm)

W

Women

BF% = 495 / (1.29579 - 0.35004×log(waist+hip-neck) + 0.22100×log(height)) - 450

Uses waist, hip, neck, and height measurements (cm or inches converted to cm)

Formula Variables

H

Height

Body height in centimeters (cm) or inches (converted to cm)

W

Waist

Waist circumference at navel level in cm or inches (converted to cm)

N

Neck

Neck circumference below Adam's apple in cm or inches (converted to cm)

Hip

Hip (Women)

Hip circumference at widest point in cm or inches (converted to cm, women only)

BF%

Body Fat %

Calculated body fat percentage

Step-by-Step Scenario

Example Scenario

Height

170 cm

Waist

80 cm

Neck

40 cm

1

Calculate Log Values

log(waist-neck) = log(40)
log(height) = log(170)

Calculate logarithmic values for the formula

2

Apply Formula

BF% = 495 / (1.0324 - 0.19077×log(40) + 0.15456×log(170)) - 450

Result: ≈20% (Average)

Additional Examples

Fit Male

Height: 175 cm

Waist: 75 cm

Neck: 38 cm

Body Fat

≈15% (Fitness)

Average Female

Height: 165 cm

Waist: 75 cm

Hip: 95 cm

Neck: 32 cm

Body Fat

≈25% (Average)

Characteristics of Body Fat Calculation

US Navy Method

Uses the US Navy body fat formula, which is ~3-4% accurate. Based on circumference measurements.

Gender Specific

Different formulas for men and women. Women's formula includes hip measurement for better accuracy.

Easy Measurement

Only requires a measuring tape. No special equipment needed. Can be done at home.

Health Tracking

Useful for tracking body composition changes over time. More meaningful than weight alone.

Important Notes

Measure waist at navel level, relaxed. Measure neck below Adam's apple. Women: measure hips at widest point.
Use a soft measuring tape, snug but not tight. Measure in the morning before eating for consistency.
The US Navy method is ~3-4% accurate. For precise measurement, use DEXA scan or hydrostatic weighing.
Body fat categories: Men - Essential (2-5%), Athletes (6-13%), Fitness (14-17%), Average (18-24%), Obese (25%+).
Women - Essential (10-13%), Athletes (14-20%), Fitness (21-24%), Average (25-31%), Obese (32%+).

Frequently Asked Questions

Find answers to common questions about body fat percentage calculation.