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Body Fat Calculator

Body Fat Calculator

Units:
Sex:

What is Body Fat Calculator?

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A body fat percentage calculator estimates fat mass as a proportion of total body weight using skinfold measurements, circumference methods (US Navy), or BMI-derived formulas.

Calkulon makes complex calculations simple — built for students and everyday problem-solvers.

Formula

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f(x)US Navy (men): %BF = 86.010×log(waist−neck) − 70.041×log(height) + 36.76; (women): 163.205×log(waist+hip−neck) − 97.684×log(height) − 78.387

Variable Legend

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SymbolNameUnitDescription
%BFBody fat percentage%—
WWaist circumferencecm—
HHeightcm—
NNeck circumferencecm—

How to Body Fat Calculator

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  1. 1US Navy method (men): 86.010×log(waist−neck) − 70.041×log(height) + 36.76
  2. 2US Navy method (women): 163.205×log(waist+hip−neck) − 97.684×log(height) − 78.387
  3. 3Jackson-Pollock: uses skinfold caliper measurements
  4. 4DEXA scan is the gold standard but requires clinical equipment

Worked Examples

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Example 1
Given:Male, waist 85cm, neck 38cm, height 178cm
Result:Body fat ≈ 86.010×log(47) − 70.041×log(178) + 36.76 ≈ 17.5%

Real-World Applications

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Fitness tracking and progress monitoring

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Athletic performance assessment

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Health risk evaluation

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Nutritionist consultation baseline

Body Fat % Categories (ACE)

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CategoryMenWomen
Essential fat2–5%10–13%
Athletes6–13%14–20%
Fitness14–17%21–24%
Acceptable18–24%25–31%
Obese25%+32%+

Frequently Asked Questions

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Q

What's a healthy body fat percentage?

A

Athletes: 6-13% (male), 14-20% (female). Fitness: 14-17% (male), 21-24% (female). Varies by age and sport.

Q

Is BMI the same as body fat %?

A

No. BMI = weight/height² and doesn't distinguish muscle from fat. Body fat % is more accurate for health.

Q

How accurate is the Navy method?

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Accurate within ±2-3%. DEXA scan (clinical) is more precise but requires equipment and cost.

For informational purposes only. This tool is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional.
Formula-verified for precision
Reviewed October 2026
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