Body Fat % Calculator (US Navy)
Estimate your body fat percentage using the US Navy circumference method.
What is Body Fat Calculator?
A Body Fat Percentage Calculator estimates the proportion of your total body weight that consists of fat mass (as opposed to lean mass — muscle, bone, water, and organs). Body fat percentage is a more informative health metric than weight or BMI alone because it directly measures fat content, whereas weight and BMI cannot distinguish between a muscular athlete and someone with excess fat at the same weight.
Several methods estimate body fat percentage without expensive clinical equipment. The most accessible is the US Navy Body Fat Formula, which uses neck, waist, and hip measurements along with height to estimate body fat percentage. The Jackson-Pollock formula uses skinfold calipers. DEXA scans and hydrostatic weighing are clinical gold standards but require specialist equipment. This calculator typically uses the Navy method as a free, validated, reasonably accurate alternative.
Healthy body fat percentage ranges differ by sex and age. For men, healthy ranges are approximately 10–20%; for women (who naturally carry more essential fat), 18–28%. Athletes typically fall below these ranges. Body fat percentage is used by fitness professionals designing training programs, bodybuilders tracking cutting progress, military and law enforcement fitness assessments, and health-conscious individuals who want metrics beyond what the scale shows.
How to Use Body Fat Calculator
- 1Step 1: Select your sex — men and women have different measurement sites and different healthy body fat percentage ranges due to essential fat differences.
- 2Step 2: Measure and enter your height. Stand straight against a wall without shoes for an accurate measurement.
- 3Step 3: Measure your waist circumference at the narrowest point (or at navel level per Navy protocol) using a flexible measuring tape. Measure at the end of a normal exhale.
- 4Step 4: For men, measure neck circumference at its narrowest point. For women, also measure hip circumference at the widest point.
- 5Step 5: Enter all measurements and click Calculate to see your estimated body fat percentage and which fitness category it falls into (essential fat, athletic, fitness, average, or obese).
Benefits of Using Body Fat Calculator
- ✓Beyond the Scale: Reveals fat mass and lean mass independently, explaining why two people at identical weights can have dramatically different health profiles and physiques.
- ✓Muscle Gain Tracking: During strength training or body recomposition, body fat percentage may decrease even as weight stays the same — this metric captures that progress.
- ✓Free Estimation Method: The Navy formula requires only a measuring tape — no expensive DEXA scan, hydrostatic tank, or bioelectrical impedance device needed.
- ✓Fitness Category Context: Places your result in a standardized fitness category (athlete, fitness, acceptable, obese) providing meaningful context beyond a bare percentage.
- ✓Health Risk Indicator: Excess body fat — particularly visceral fat reflected in high waist measurements — is strongly linked to cardiovascular disease, insulin resistance, and inflammation.
- ✓Realistic Goal Setting: Set body composition goals (e.g., reach 18% body fat) that reflect actual fitness rather than an arbitrary number on a scale.
Example
About Body Fat Calculator
Body Fat Calculator estimates your body fat percentage using the US Navy method based on waist, neck, hip, and height measurements. It classifies your result by fitness category and shows the estimated lean body mass. Supports metric and imperial measurements.
- US Navy measurement method
- Body fat percentage estimate
- Fitness category classification
- Lean mass calculation