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Body Fat Calculator

Calculate your body fat percentage using the US Navy method. Enter your measurements to estimate body fat and see how you compare to fitness categories.

Examples

Athletic male

175 cm, neck 38 cm, waist 78 cm — about 11.0% (athletic).

Gender
Male
Height
68.898 in
Neck Circumference
14.961 in
Waist Circumference
30.709 in
Body Fat Percentage
11 %
Category
Athletic

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How It Works

Formula

BFmale=86.010×log⁡10(w−n)−70.041×log⁡10(h)+36.76\text{BF}_{\text{male}} = 86.010 \times \log_{10}(w - n) - 70.041 \times \log_{10}(h) + 36.76

BFfemale=163.205×log⁡10(w+H−n)−97.684×log⁡10(h)−78.387\text{BF}_{\text{female}} = 163.205 \times \log_{10}(w + H - n) - 97.684 \times \log_{10}(h) - 78.387

Variables, symbols and units

BF\text{BF}

Body fat percentage(%)

ww

Waist circumference(in)

nn

Neck circumference(in)

HH

Hip circumference (women only)(in)

hh

Height(in)
Calculation method explained

The US Navy method uses logarithmic formulas applied to circumference measurements and height, all in inches. Metric entries are converted to inches before the formula is applied. For men, it uses neck and waist; for women, it adds hip circumference. The result is compared against standard body fat categories to classify your fitness level.

The US Navy coefficients are calibrated to inches, so any centimetre input is converted via 1 in=2.54 cm1\,\text{in} = 2.54\,\text{cm} before the equation is evaluated. The male formula uses waist minus neck; the female formula adds hip circumference to capture sex-specific fat distribution. The resulting percentage is then matched to a fitness band (essential, athletic, fitness, average, above average).

References and source material

Examples

Athletic maleMale · 68.898 in → 11 %

175 cm, neck 38 cm, waist 78 cm — about 11.0% (athletic).

Gender
Male
Height
68.898 in
Neck Circumference
14.961 in
Waist Circumference
30.709 in
Body Fat Percentage
11 %
Average femaleFemale · 64.961 in → 29.7 %

165 cm, neck 33 cm, waist 75 cm, hip 100 cm — about 29.7% (average).

Gender
Female
Height
64.961 in
Neck Circumference
12.992 in
Waist Circumference
29.528 in
Hip Circumference
39.37 in
Body Fat Percentage
29.7 %
Fitness-focused maleMale · 70.866 in → 11.9 %

180 cm, neck 40 cm, waist 82 cm — about 11.9% (athletic).

Gender
Male
Height
70.866 in
Neck Circumference
15.748 in
Waist Circumference
32.283 in
Body Fat Percentage
11.9 %

Frequently Asked Questions

What is the US Navy method?
The US Navy method estimates body fat percentage from simple circumference measurements (neck, waist, and hip for women) combined with height. It is useful for screening and trend tracking.
How accurate is this method?
This is a tape-measure estimate, not a clinical body-composition test. It is less direct than DEXA scans or hydrostatic weighing but more accessible for tracking trends over time.
Why do women need hip measurements?
Women typically carry more fat in the hip and thigh area. The hip circumference helps account for this difference in fat distribution, making the estimate more accurate for women.
What body fat percentage is healthy?
Treat the category label here as a rough fitness-oriented band, not a medical judgment about healthy or unhealthy body fat.
How should I measure my circumferences?
Use a flexible tape measure. Measure your neck at the narrowest point below the Adam's apple. Measure your waist at the navel level. Measure hips at the widest point. Keep the tape snug but not tight, and measure on bare skin.

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