Body Fat Calculator
Enter your height, waist, neck and (for women) hip measurements to estimate your body fat percentage using the US Navy circumference method.
Body Fat Calculator
Estimate body fat percentage from measurements
Body fat % is estimated from circumference measurements using the US Navy formula, which differs for men and women. Results are estimates — actual body fat varies with measurement technique.
US Navy Body Fat Method
The US Navy circumference method estimates body fat from tape measurements:
**Men**: 86.010×log₁₀(abdomen − neck) − 70.041×log₁₀(height) + 36.76 **Women**: 163.205×log₁₀(waist + hip − neck) − 97.684×log₁₀(height) − 78.387
All measurements in inches.
**Body fat categories (men)**: Essential 2–5%, Athletic 6–13%, Fitness 14–17%, Average 18–24%, Obese 25%+ **Body fat categories (women)**: Essential 10–13%, Athletic 14–20%, Fitness 21–24%, Average 25–31%, Obese 32%+
**Measurement tips**: Use a flexible tape, measure bare skin, keep tape horizontal and snug but not tight, measure after exhaling.
- US Navy circumference method
- Different formulas for men and women
- All measurements in inches
- Tape snug but not tight, after exhaling
Worked Example
Example: Male, 70 inches tall, neck 15 inches, waist 32 inches.
- abdomen − neck = 32 − 15 = 17 - log₁₀(17) = 1.230, log₁₀(70) = 1.845 - BF = 86.010×1.230 − 70.041×1.845 + 36.76 - BF = 105.8 − 129.2 + 36.76 ≈ 13.4% - Category: Athletic
Related Calculators
Waist-to-Hip Ratio Calculator
Calculate WHR and assess health risk from waist and hip measurements.
Open calculator →Calories Burned Calculator
Estimate calories burned during exercise from activity, weight and duration.
Open calculator →BMR Calculator
Calculate Basal Metabolic Rate — calories your body burns at rest.
Open calculator →Target Heart Rate Calculator
Calculate your target heart rate zones for fat burn, cardio and peak training.
Open calculator →Frequently Asked Questions
How accurate is the Navy method?
Within ~3–4 percentage points of more accurate methods like DEXA or hydrostatic weighing for most people. It's a good tracking tool but not perfectly precise.
Why do women need a hip measurement?
Women store proportionally more fat in the hips and thighs, so the hip measurement improves the estimate's accuracy.
Looking for a different calculator?
CalculatorPlus has free tools across finance, construction, math, health and more — each one showing the formula and a worked example.