Health
Body Fat Calculator
Estimate your body fat percentage using the US Navy circumference method. Works for both men and women in metric and imperial units.
Body Fat Percentage
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Body Fat Categories (Men)
< 6% Essential6–13% Athletes14–17% Fitness18–24% Average25%+ Obese
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US Navy Body Fat Formula
Men
BF% = 495 ÷ (1.0324 − 0.19077×log(waist−neck) + 0.15456×log(height)) − 450
Women
BF% = 495 ÷ (1.29579 − 0.35004×log(waist+hip−neck) + 0.22100×log(height)) − 450
How to Take Measurements
Height: Measure without shoes, standing upright against a wall.
Waist:Measure at the navel (belly button). Stand relaxed, don't suck in. Take the measurement at the end of a normal exhale.
Neck:Measure just below the larynx (Adam's apple), with the head level.
Hips (women only): Measure at the widest point of the hips and buttocks.
Frequently asked questions
What is the Navy body fat method?
The US Navy circumference method estimates body fat percentage using simple tape measurements: height, waist (at the navel), and neck for men; plus hips for women. These are plugged into a formula validated against hydrostatic weighing and DEXA scans. It is considered accurate to within 3–4% for most people.
What is a healthy body fat percentage?
For men, 6–13% is athletic, 14–17% is fitness range, and 18–24% is average. Above 25% is considered obese. For women, 14–20% is athletic, 21–24% is fitness, 25–31% is average, and above 32% is considered obese. Essential fat (the minimum needed for health) is around 3–5% for men and 10–13% for women.
How accurate is the Navy method?
The Navy method is reasonably accurate for most adults, typically within 3–4% of more clinical methods like DEXA. It is less accurate for very lean individuals (below 10% BF) and for older adults with low muscle mass. For clinical precision, a DEXA scan or hydrostatic weighing is more reliable.
Where should I measure waist circumference for body fat?
For the Navy method, waist should be measured at the navel (belly button level), not at the smallest part of the waist as in clothing measurements. Men typically measure at the largest point around the midsection. Measure straight around without sucking in or pushing out.
What is the difference between body fat percentage and BMI?
BMI uses only height and weight, making it a proxy measure that cannot distinguish between fat and muscle. A muscular person can have a 'overweight' BMI but a healthy body fat percentage. Body fat percentage directly measures the proportion of fat tissue and is a better indicator of health and body composition.