📊 Fitness Tool
Body Fat Calculator
Estimate your body fat percentage using the U.S. Navy circumference method — a simple, proven approach requiring only a tape measure.
Body Fat Calculator (Navy Method)
Body Fat Percentage
--%
Fat Mass
--
kg
Lean Mass
--
kg
| Category | Women | Men |
|---|---|---|
| Essential Fat | 10–13% | 2–5% |
| Athletes | 14–20% | 6–13% |
| Fitness | 21–24% | 14–17% |
| Acceptable | 25–31% | 18–24% |
| Obese | 32%+ | 25%+ |
How Is Body Fat % Calculated?
This tool uses the U.S. Navy Circumference Method, developed by Hodgdon and Beckett (1984). It estimates body fat based on height and key body measurements.
Men: %BF = 495 / (1.0324 − 0.19077×log10(waist−neck) + 0.15456×log10(height)) − 450
Women: %BF = 495 / (1.29579 − 0.35004×log10(waist+hip−neck) + 0.22100×log10(height)) − 450
Women: %BF = 495 / (1.29579 − 0.35004×log10(waist+hip−neck) + 0.22100×log10(height)) − 450
How to Measure Correctly
- Neck: Measure just below the larynx (Adam's apple), sloping slightly downward at the front
- Waist (Men): At the navel level
- Waist (Women): At the smallest point, usually 1 inch above the navel
- Hip (Women only): At the widest point of the hips/buttocks
Frequently Asked Questions
What is a healthy body fat percentage?
For women, 21–31% is considered acceptable; 14–20% is the fitness/athlete range. For men, 18–24% is acceptable; 6–17% is the athlete/fitness range. Essential fat (necessary for life) is 10–13% for women and 2–5% for men.
Is the Navy method accurate?
The U.S. Navy method has an accuracy within 3–4% compared to more precise methods like DEXA scans or hydrostatic weighing. For most people, it provides a reliable estimate without expensive equipment.
How can I reduce body fat?
The most effective approach combines a moderate calorie deficit (500 kcal/day), adequate protein intake (1.6–2.2 g/kg body weight), resistance training, and cardiovascular exercise. Spot reduction is a myth — fat loss occurs throughout the body.