Body Fat Calculator
Estimate your body fat percentage using the U.S. Navy method. Just enter height, weight, and circumference measurements.
Last updated: 2026-03-07
Body fat calculator
Enter your measurements
Uses the US Navy body fat formula. Measure waist at navel, neck at narrowest point.
Body Fat
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Enter your measurements to estimate body fat percentage.
Calculation History (0)
Example calculations
Tap an example to prefill the calculator with sample values.
Average Male
5'10", 180 lb, 36" waist, 15" neck
A male with average build and moderate activity level.
Result: ~19.7% body fat — Average
Fit Female
5'6", 135 lb, 28" waist, 13" neck, 36" hip
An active woman who exercises regularly.
Result: ~24.1% body fat — Fitness
Athletic Male
6'0", 195 lb, 33" waist, 16" neck
A man who strength trains 4-5 times per week.
Result: ~14.0% body fat — Athletes
How the body fat calculator works
This calculator uses the U.S. Navy body fat formula, a circumference-based method developed by Hodgdon and Beckett that estimates body fat percentage from simple tape measurements.
Male formula: %BF = 495 / (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450
Female formula: %BF = 495 / (1.29579 − 0.35004 × log10(waist + hip − neck) + 0.22100 × log10(height)) − 450
Body fat categories (ACE):
- 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%+
For best accuracy, take measurements in the morning before eating. Measure waist at the navel, neck at the narrowest point below the Adam's apple, and hips at the widest point.
Body fat calculator FAQs
Answers to common body composition questions.
How accurate is the U.S. Navy body fat method?
The U.S. Navy method is accurate to within 1–3% of hydrostatic weighing for most people. It's the standard used by the U.S. military for fitness assessments. For very muscular or very lean individuals, it may be less accurate.
What's a healthy body fat percentage?
For men, 14–24% is considered average/healthy. For women, 21–31% is average/healthy. Athletes typically have lower body fat (6–13% for men, 14–20% for women). Essential fat levels (below 5% for men, below 13% for women) should not be maintained long-term.
How should I take measurements?
Use a flexible tape measure against bare skin. Measure waist horizontally at navel level, neck at the narrowest point below the Adam's apple, and hips (women only) at the widest point. Take measurements in the morning before eating for consistency.
Why do women need a hip measurement?
Women store more fat in the hip and thigh region. The Navy formula accounts for this sex-based difference by including the hip circumference measurement in the female equation to improve accuracy.
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Disclaimer
This calculator provides estimates based on the U.S. Navy circumference method. Results may vary from clinical measurements. Consult a healthcare provider for accurate body composition analysis and health guidance.
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