Body Fat Calculator
Use height and circumference measurements to estimate your body fat percentage with the US Navy Method.
Body Fat Categories
| Category | Men | Women |
|---|---|---|
| Essential Fat | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Acceptable | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |
The US Navy Method Formula
The Navy method uses circumference measurements to estimate body density, then converts to body fat percentage:
All measurements in centimeters.
Frequently Asked Questions
How does the US Navy body fat method work?
The US Navy method uses circumference measurements — height, waist, neck, and hips (women only) — to estimate body fat percentage through a logarithmic formula. While not as precise as DEXA scans or hydrostatic weighing, studies show it's accurate within 3–4 percentage points for most people and correlates well with more expensive methods.
Where exactly should I measure my waist and neck?
For men: measure the waist at the navel (horizontally, not sucked in). For women: measure at the narrowest point between the ribs and hips. For both sexes: measure the neck just below the larynx (Adam's apple), slightly angled downward at the front. Take measurements in the morning before eating for consistency.
What is a healthy body fat percentage?
Healthy ranges vary by sex. For men: essential fat 2–5%, athletes 6–13%, fitness 14–17%, acceptable 18–24%, obese 25%+. For women: essential fat 10–13%, athletes 14–20%, fitness 21–24%, acceptable 25–31%, obese 32%+. Athletes typically aim for the lower end; general health goals fall in the acceptable range.
How is body fat percentage different from BMI?
BMI uses only height and weight, which means it can't distinguish between fat and muscle. A muscular athlete can have an 'overweight' BMI despite low body fat. Body fat percentage directly measures fat as a proportion of total body weight, making it a more meaningful metric for health and body composition.
How can I reduce body fat percentage?
The most effective approach combines a calorie deficit (for fat loss) with resistance training (to preserve muscle mass). Even a modest 250–500 kcal/day deficit reduces fat while maintaining strength. Protein intake of 0.7–1.0 g per lb of body weight helps preserve muscle during a cut.