Health
Body Fat Calculator
Estimate body fat % using the US Navy circumference method.
Body Fat Percentage
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Body Fat %
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Lean Mass %
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Category
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Healthy Range
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How to Measure
Neck
Measure below the larynx (Adam's apple), perpendicular to the neck axis. Keep tape snug, not tight.
Waist
Males: measure at the navel. Exhale naturally before measuring.
Hips (females only)
Measure at the widest point of the hips/buttocks. Keep feet together.
Body Fat Categories
| Category | Men | Women |
|---|---|---|
| Essential fat | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |
Navy Method Formula
Males
495 ÷ (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450
Females
495 ÷ (1.29579 − 0.35004 × log₁₀(waist + hip − neck) + 0.22100 × log₁₀(height)) − 450
All measurements in centimeters. Developed by the US Navy; used by DoD for fitness assessments.
Accuracy
Navy method estimates body fat within ±3–4% of DEXA scan results for most people. Accuracy drops at very high or very low body fat levels. For clinical assessment, consult a healthcare provider.
FAQ
Frequently asked questions.
What is a healthy body fat percentage?
A healthy body fat percentage varies by sex and age. For women, 20–32% is considered healthy, while for men the healthy range is 8–19%. Athletes typically fall below these ranges, while percentages above 32% for women and 25% for men are associated with increased health risks.
How accurate is a body fat percentage calculator?
Online body fat calculators using the U.S. Navy circumference method are reasonably accurate, with a typical margin of error of 3–4 percentage points. They are less precise than DEXA scans or hydrostatic weighing, but provide a reliable, cost-free estimate for most people tracking general fitness progress.
What measurements do I need to calculate body fat?
The U.S. Navy method requires your height, weight, neck circumference, and waist circumference. Women also need their hip circumference. These simple tape-measure inputs are enough to estimate body fat percentage without any special equipment.
What is the difference between body fat percentage and BMI?
BMI (Body Mass Index) uses only height and weight to classify weight status, and cannot distinguish between fat and muscle mass. Body fat percentage directly measures the proportion of fat in your total body weight, making it a more meaningful indicator of fitness and metabolic health, especially for muscular individuals.
How can I reduce my body fat percentage?
Reducing body fat typically requires a combination of a moderate calorie deficit, regular cardiovascular exercise, and resistance training to preserve or build lean muscle. Consistency over weeks and months produces sustainable results, and tracking your body fat percentage periodically helps you measure real progress beyond the scale.
What is lean body mass?
Lean body mass is the weight of everything in your body except fat — including muscle, bone, organs, blood, and water. It is calculated by subtracting your fat mass from your total body weight. Preserving or increasing lean mass is a key goal during fat-loss programs because muscle raises your resting metabolic rate.
Which body fat calculation method is most accurate?
DEXA (dual-energy X-ray absorptiometry) scans are considered the gold standard for body fat measurement. Among at-home methods, skinfold calipers performed by a trained professional and the U.S. Navy circumference method are the most reliable, both typically within 3–5% of DEXA results.
Last updated: August 17, 2026