⚡ Health Tool

Body Fat Calculator

Scientifically accurate body fat percentage using the U.S. Navy & BMI Methods. Trusted by health professionals worldwide.

Your Measurements
Units:
yrs
kg
cm
cm
cm

U.S. Navy Method — Developed by the U.S. Department of Defense. Uses neck, waist (and hip for women) measurements. Clinically validated with ±3–4% accuracy compared to DEXA scans.

Your Results
Body Fat %
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—
Fat Mass
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kg
Lean Body Mass
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kg
BMI (estimated)
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kg/m²
EssentialAthleteFitnessAverageObese
Category Breakdown
Category Range Yours
Health Insight
What To Do Next

How Does This Body Fat Calculator Work?

This calculator uses two scientifically validated methods to estimate body fat percentage — no calipers or expensive equipment needed.

U.S. Navy Method

Developed by the U.S. Department of Defense, this formula uses neck, waist (and hip for women) circumferences along with height. It achieves ±3–4% accuracy compared to DEXA scans — the gold standard of body composition analysis. Formulas used:

Men: %BF = 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76

Women: %BF = 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387

BMI Method

Uses BMI, age, and sex as inputs. Less precise than the Navy Method for muscular individuals but a useful secondary estimate when circumference measurements aren't available.

%BF = 1.20 × BMI + 0.23 × Age − 16.2 (men) / − 5.4 (women) — Deurenberg Formula (1991).

Body Fat Categories (American Council on Exercise)

The ACE classifies body fat as: Essential Fat (men 2–5%, women 10–13%), Athletes (men 6–13%, women 14–20%), Fitness (men 14–17%, women 21–24%), Average (men 18–24%, women 25–31%), Obese (men 25%+, women 32%+).

Accuracy & Limitations

No circumference-based method perfectly replaces DEXA, hydrostatic weighing, or BodPod. Results may vary for very muscular individuals, the elderly, or those with unusual body proportions. Use this as a consistent tracking tool rather than an absolute measurement.