How accurate is the Navy body fat method?

The Navy method is accurate within 3-4% for most people. It's less accurate for very lean or very muscular individuals. For precise measurements, DEXA scans or hydrostatic weighing are more reliable.

What is a healthy body fat percentage?

For men: 10-20% is considered fit, 20-25% is acceptable. For women: 18-28% is fit, 25-31% is acceptable. Essential fat minimums are about 3% for men and 12% for women.

How do I measure my neck and waist?

Measure your neck at the narrowest point below the Adam's apple. Measure your waist at the navel level while exhaling normally. For women, also measure hips at the widest point. Use a flexible tape measure snug against the skin.

Is BMI or body fat percentage more useful?

Body fat percentage is more useful because it distinguishes muscle from fat. BMI treats all weight the same, so a muscular athlete can have a 'overweight' BMI while actually being very lean.

Body Fat Calculator — Estimate Your Body Fat Percentage

Body Fat Calculator

Estimate your body fat percentage using the U.S. Navy tape-measure method.

Sex

Units

Height (inches)

Weight (lbs)

Waist (inches) at navel

Neck (inches) narrowest point

📐 How We Calculate — Learn about our calculation methodology, data sources, and quality standards.

The U.S. Navy Method

Developed by Hodgdon and Beckett in 1984 for the U.S. Navy, this tape-measure method estimates body fat from body circumference and height. It avoids expensive equipment and correlates reasonably well (±3%) with hydrostatic weighing for most adults.

How the Formula Works

Men: %BF = 495 / (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450
Women: %BF = 495 / (1.29579 − 0.35004 × log₁₀(waist + hip − neck) + 0.22100 × log₁₀(height)) − 450

Measure waist at the navel for men and at the narrowest point for women. Neck measurement is taken just below the larynx. All measurements in centimeters for best accuracy.

Body Fat Category Ranges

Essential fat is the minimum needed for organ function: ~3% for men, ~12% for women. Athletes typically carry 6–13% (men) or 14–20% (women). The fitness range is 14–17% / 21–24%. Above 25% for men or 32% for women is generally classified as obese.

Improving Your Body Composition

Body fat percentage responds to a combination of resistance training (preserves lean mass), calorie control, and adequate protein intake (1.6–2.2 g/kg body weight). Aiming to lose 0.5–1% body fat per month is sustainable without sacrificing muscle.

Frequently Asked Questions

Is this more accurate than BMI?

The Navy method directly estimates body composition rather than using weight-to-height ratio. It catches cases where high muscle mass inflates BMI, but is still an estimate — DEXA scans and hydrostatic weighing are more precise.

How often should I measure?

Every 4–6 weeks gives enough time to see meaningful changes. Daily measurements are noisy due to hydration shifts. Use the same time of day (morning, post-void) each time for consistency.

Why does the formula need hip for women but not men?

Women typically store more fat around the hips and thighs (gynoid pattern). Including hip circumference improves prediction accuracy for female body composition compared to using waist alone.

Body Fat Calculator

Your Results

The U.S. Navy Method

How the Formula Works

Body Fat Category Ranges

Improving Your Body Composition

Frequently Asked Questions

Related Calculators

BMI Calculator

Calorie Calculator

Age Calculator