How accurate is the US Navy body fat method?

The US Navy method is accurate to within 1-3% of hydrostatic weighing for most people. It tends to be more accurate for individuals in the normal weight range and may underestimate body fat in very lean or very overweight individuals.

What is a healthy body fat percentage?

For men, 10-20% is considered healthy and fit, while 21-24% is acceptable. For women, 18-28% is healthy and fit, while 29-31% is acceptable. Essential fat is 2-5% for men and 10-13% for women.

Where exactly do I measure my waist for this calculator?

For men, measure at the navel (belly button) level. For women, measure at the narrowest point of your waist, typically just above the navel. Stand relaxed, do not suck in your stomach, and keep the tape snug but not tight.

Is body fat percentage more useful than BMI?

Body fat percentage is generally more informative than BMI because it measures actual fat, not just weight relative to height. A muscular person may have a high BMI but low body fat. However, both measures have value when used together.

Body Fat Percentage Calculator

This Body Fat Percentage Calculator uses the US Navy method to estimate your body fat from simple tape measurements. All you need is a tape measure and your height, neck, waist, and hip circumference to get an accurate estimate without expensive equipment.

Enter Your Details

Gender

Height

Weight

Neck circumference

Measure at the narrowest point

Waist circumference

Measure at the navel

How It Works

The US Navy method uses a logarithmic formula based on circumference measurements. For men, the formula uses neck and waist measurements relative to height. For women, it also includes hip circumference. The formula correlates strongly with hydrostatic weighing, the gold standard for body fat measurement.

Quick Reference

Category	Men	Women
Essential fat	2-5%	10-13%
Athletic	6-13%	14-20%
Fitness	14-17%	21-24%
Average	18-24%	25-31%
Above average	25%+	32%+

Categories from the American Council on Exercise (ACE). Healthy ranges vary by age.

Frequently Asked Questions

How accurate is the US Navy body fat method?: The US Navy method is accurate to within 1-3% of hydrostatic weighing for most people. It tends to be more accurate for individuals in the normal weight range and may underestimate body fat in very lean or very overweight individuals.
What is a healthy body fat percentage?: For men, 10-20% is considered healthy and fit, while 21-24% is acceptable. For women, 18-28% is healthy and fit, while 29-31% is acceptable. Essential fat is 2-5% for men and 10-13% for women.
Where exactly do I measure my waist for this calculator?: For men, measure at the navel (belly button) level. For women, measure at the narrowest point of your waist, typically just above the navel. Stand relaxed, do not suck in your stomach, and keep the tape snug but not tight.
Is body fat percentage more useful than BMI?: Body fat percentage is generally more informative than BMI because it measures actual fat, not just weight relative to height. A muscular person may have a high BMI but low body fat. However, both measures have value when used together.

US Navy Body Fat Formula

Men: 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76 Women: 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387

waist: = waist circumference in cm
neck: = neck circumference in cm
hip: = hip circumference in cm (women only)
height: = height in cm

All measurements are in centimetres. The US Navy method was developed in 1984 by Hodgdon and Beckett and correlates well with hydrostatic weighing.

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Disclaimer

This calculator provides estimates for informational purposes only and should not be considered medical advice. Individual results may vary based on factors not captured by these formulas. Consult a healthcare professional before making changes to your diet or exercise routine, especially if you have any existing health conditions.