Body Fat Percentage Calculator
Estimate body fat percentage using the U.S. Navy method.
Height
Neck
Waist
Body Fat
17.8%
Category
Average
Estimated using the U.S. Navy circumference method. Accuracy varies by body type — for precise readings, consider a DEXA scan or skinfold measurement.
How this calculator works
The U.S. Navy method estimates body fat from a log-based formula using neck, waist and (for women) hip circumference relative to height — no calipers or scanning equipment needed, just a tape measure. It was developed in the early 1980s for military fitness screening, where testing thousands of recruits with skinfold calipers or underwater weighing wasn't practical.
How to measure accurately
Measure your neck just below the larynx (Adam's apple), and your waist at the narrowest point — for men this is usually just above the navel; for women, around the smallest part of the torso. Women also measure hips at the widest point. Use a soft tape pulled snug but not compressing the skin, and measure at the same time of day (ideally first thing in the morning, on an empty stomach) for consistent tracking over time.
Why men and women use different formulas
Men and women store and distribute body fat differently on average, so the Navy method uses separate equations: the men's formula uses waist minus neck circumference, while the women's formula adds hip circumference into the calculation as well, since fat distribution around the hips is a more relevant factor for women's body composition estimates.
How accurate is it?
Studies generally find the Navy method within about 3-4 percentage points of more precise methods like DEXA scanning for most body types, though it becomes less reliable at the extremes — very lean athletes and people with obesity tend to see larger errors than someone in the middle of the range. It's a solid free estimate for tracking trends over time, not a substitute for a clinical body composition scan if you need precise numbers.
What the categories mean
The essential fat category is the minimum needed for basic physiological function — going below it for extended periods is unhealthy, not an achievement. For a complementary read on weight relative to height instead of body composition, see the BMI Calculator.
Frequently Asked Questions
How is body fat percentage calculated here?
This tool uses the U.S. Navy circumference method, which estimates body fat from neck, waist and (for women) hip measurements combined with height — no calipers or scans required.
How accurate is the Navy method compared to a DEXA scan?
It's typically within a few percentage points of more precise methods like DEXA or hydrostatic weighing for most body types, which makes it a reasonable at-home estimate, though not a clinical-grade measurement.
What's a healthy body fat percentage?
Ranges vary by sex and age, but commonly cited healthy ranges are roughly 10–20% for men and 18–28% for women, with athletes often sitting lower. This calculator shows where your result falls on that scale.
How do I measure my neck and waist correctly?
Measure your neck just below the larynx and your waist at its narrowest point (just above the navel for men, the smallest part of the torso for women), using a soft tape pulled snug but not compressing the skin. Women also measure hips at their widest point.
Why does the formula differ for men and women?
Men and women distribute body fat differently on average. The men's formula uses waist minus neck circumference; the women's formula also factors in hip circumference, since hip fat distribution is more relevant to body composition estimates for women.
This tool provides general estimates for informational purposes only and isn't a substitute for professional medical advice. Consult a doctor or qualified healthcare provider before making decisions about your health.