Body Fat Calculator
Enter your height and body measurements to estimate your body fat percentage using the U.S. Navy method.
Last updated: September 5, 2026
Frequently asked questions
How accurate is the U.S. Navy body fat method?
It's generally within 3–4% of more precise methods like DEXA scans for most body types, making it a reasonably reliable estimate without special equipment.
Why does the formula use neck and waist measurements?
The Navy method correlates body fat with the ratio between waist (and hip, for women) circumference relative to neck circumference and height - larger waist-to-neck ratios generally indicate higher body fat.
How does the U.S. Navy method compare to other body fat measurement methods?
It's less precise than methods like DEXA scans or hydrostatic weighing, but it's far more accessible since it only needs a tape measure - it's generally considered reasonably accurate for tracking trends over time, even if the absolute number carries more error than a clinical method.
Can I use the U.S. Navy method to track progress over time?
Yes - because it only requires a tape measure and no special equipment, it's a practical way to track relative body composition changes over weeks or months, even though its absolute accuracy is lower than methods like DEXA scans for any single measurement.
What's an example body fat calculation?
For a man 5'10" (70 in) with a 15-inch neck and 34-inch waist, the Navy formula estimates roughly 15% body fat - a range generally considered fit/athletic.
Why does the formula need hip measurement for women but not men?
The Navy method uses a different equation for each sex - women's body fat distribution is more influenced by hip circumference, so the formula for women adds a hip measurement term that isn't in the men's equation, which uses only neck and waist.
What counts as a healthy body fat percentage?
General ranges are roughly 10-20% for men and 18-28% for women, though healthy ranges shift with age and athletic goals. These are broad guidelines, not medical thresholds - a doctor or sports medicine professional can interpret your number in context.