How is Body Fat Calculated? (Navy Method)
The U.S. Navy Method estimates body fat percentage using simple body measurements. It is a widely used and reasonably accurate method for most people.
- For men: Body fat % = 495 / (1.0324 - 0.19077 × log'10'(waist - neck) + 0.15456 × log'10'(height)) - 450
- For women: Body fat % = 495 / (1.29579 - 0.35004 × log'10'(waist + hip - neck) + 0.22100 × log'10'(height)) - 450
Example Calculation
Suppose a male is 180 cm tall, with a neck of 40 cm and a waist of 90 cm:
Body fat % = 495 / (1.0324 - 0.19077 × log10(90 - 40) + 0.15456 × log10(180)) - 450 ≈ 495 / (1.0324 - 0.3245 + 0.3486) - 450 ≈ 495 / 1.0565 - 450 ≈ 468.5 - 450 = 18.5%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+ |
FAQs
- How accurate is the Navy Method?
It is reasonably accurate for most people, but not as precise as DEXA scans or hydrostatic weighing. - What is a healthy body fat percentage?
See the table above for healthy ranges by gender. - Can I use inches instead of centimeters?
Convert inches to centimeters by multiplying by 2.54.