Body Fat Calculator
Estimate your body fat percentage using the U.S. Navy method — just height, waist, neck, and hip measurements.
This tool is for informational purposes only and is not medical advice. Consult a healthcare professional for health guidance.
Body Fat Ranges (ACE)
| Category | Men | Women |
|---|---|---|
| Essential Fat | 2–5% | 10–13% |
| Athlete | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Obese | ≥ 25% | ≥ 32% |
Measurement tips
- Waist: measure at navel level, abdomen relaxed, at the narrowest point
- Neck: measure just below the larynx (Adam's apple), tape angled slightly downward
- Hip (women): measure at the widest point around the buttocks
Frequently Asked Questions
The U.S. Navy circumference method is accurate to within 3–4% compared to hydrostatic weighing (the gold standard). It is more accessible than DEXA scans or calipers and gives consistent results when measurements are taken correctly. The key is measuring at the right anatomical landmarks — the calculator provides tips for each measurement.
For the Navy formula, measure your waist at navel level with your abdomen relaxed — not at the narrowest point (as is common for clothing). Stand straight, exhale normally, and take the measurement at the end of a normal breath. Do not suck in your stomach.
According to the American Council on Exercise (ACE), healthy ranges are: Men: 14–17% (fitness), 6–13% (athlete), 2–5% (essential). Women: 21–24% (fitness), 14–20% (athlete), 10–13% (essential). Average ranges are 18–24% for men and 25–31% for women. Above 25% (men) or 32% (women) is classified as obese.
Lean body mass (LBM) is everything in your body except fat — muscles, bones, organs, and water. Knowing your LBM helps you set smarter fitness goals: gaining muscle while losing fat keeps your weight stable but improves body composition. LBM also determines your basal metabolic rate and protein needs.