How accurate is this method?

The Navy method is a reasonable field estimate but is less accurate than DEXA scans or hydrostatic weighing.

Body Fat Percentage Calculator

This calculator uses the U.S. Navy method, which estimates body fat percentage from neck, waist, height, and (for women) hip measurements.

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Results

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Formula

US Navy circumference method (log-based formula, sex-specific)

Understanding Your Health Numbers: BMI, BMR, and Body Composition Explained

What BMI, BMR, and body fat percentage formulas actually measure, their limitations, and how to interpret your results.

What BMI Actually Measures (and What It Doesn't)

The BMI formula explained with a worked example, its historical origin, and why it shouldn't be read in isolation.

How the U.S. Navy Body Fat Method Actually Works

The circumference-based body fat formula explained, including why it uses logarithms and how accurate it really is.

BMI Calculator

Calculate your Body Mass Index from your height and weight.

Ideal Weight Calculator

Estimate ideal body weight using the Devine formula.

BMR Calculator

Calculate your Basal Metabolic Rate using the Mifflin-St Jeor equation.

TDEE Calculator

Calculate your Total Daily Energy Expenditure based on activity level.

Daily Calorie Calculator

Calculate daily calorie needs to maintain, lose, or gain weight.

Daily Water Intake Calculator

Estimate how much water you should drink per day based on your weight.