Body Fat Percentage Calculator
Estimate your body fat % using the US Navy circumference method — one of the most accessible and validated tape-measure techniques. Get your fat mass, lean mass, body fat category, and a more accurate TDEE using the Katch-McArdle formula.
- Height: Stand straight against a wall, measure in the morning
- Neck: Measure just below the larynx (Adam's apple), tape slightly downward at front
- Waist (Men): At the narrowest point, or at the navel — measure relaxed, not sucked in
- Waist (Women): At the narrowest point of the torso, between ribs and navel
- Hip (Women only): At the widest point of the hips/buttocks
- Take each measurement 3 times and use the average for best accuracy
What Is the US Navy Body Fat Method?
The US Navy circumference method was developed by Hodgdon and Beckett at the Naval Health Research Center in 1984. It estimates body fat percentage using simple tape measurements — height, neck, waist, and (for women) hip circumferences — without requiring specialized equipment like hydrostatic weighing or DEXA scans.
While not as precise as DEXA (which is accurate to ±1–2%), the Navy method is accurate within approximately ±3–4% when measurements are taken correctly, making it practical and highly accessible.
How Body Fat % Connects to Your TDEE
Knowing your body fat percentage unlocks the Katch-McArdle formula for calculating BMR — which uses lean body mass instead of total body weight. This is significantly more accurate for:
- Athletes and bodybuilders with above-average muscle mass
- Very overweight individuals where total weight overestimates metabolic tissue
- Anyone who has had body composition results from DEXA or other methods
Use your body fat result from this calculator in the TDEE Calculator (select "Katch-McArdle" formula) for the most accurate maintenance calorie estimate.
Take all measurements in the morning before eating or drinking. Measure each site three times and use the average. Keep the tape snug but not compressing the skin. Consistent measuring technique is more important than technique itself — always use the same method for progress tracking.
Body Fat % Goals for Different Purposes
| Category | Men | Women | Notes |
|---|---|---|---|
| Essential Fat | 2–6% | 10–14% | Minimum for physiological function |
| Athlete | 6–14% | 14–21% | Competitive sport range |
| Fitness | 14–18% | 21–25% | Healthy, lean physique |
| Acceptable | 18–25% | 25–32% | Average healthy adult |
| Obese | 25%+ | 32%+ | Elevated metabolic risk |
Source: American Council on Exercise (ACE) body fat percentage norms.