Body Fat Calculator
Estimate body fat percentage using the U.S. Navy method
Calculate with Body Fat Calculator
Your Body Fat
Body Composition
Body Fat Categories
Your result
Method, context, and limits
Use these notes to understand what the estimate is based on, when it helps, and where it can drift.
Most online body-fat estimates use circumference formulas such as the U.S. Navy method rather than direct imaging.
Use this tool when you want a simple body-composition check for trend tracking, not a clinical or lab-grade test.
Tape placement, hydration, and body-shape differences can move the estimate noticeably.
Health use guide
Uses circumference-based methods to estimate body-fat range when you want more context than scale weight alone can give.
About This Tool
Understanding Body Fat Percentage and Health
Body fat percentage estimates the share of total body weight made up of adipose tissue, adding context that weight or BMI alone cannot provide. This calculator uses circumference inputs, so the result is a field estimate rather than a laboratory body-composition measurement. Essential fat supports hormone production, organ protection, temperature regulation, and nutrient absorption, while storage fat serves as energy reserve and insulation. Body-fat interpretation varies by age, sex, training status, measurement method, and health history, so use the result for trend tracking and planning conversations rather than diagnosis.
The U.S. Navy Body Fat Calculation Method
This calculator uses the U.S. Navy circumference method, a practical field estimate that requires only a tape measure. The formula uses height and circumference measurements at specific landmarks: neck at the narrowest point below the larynx, waist at navel level for men, and waist plus hip at the widest point for women. Male formula: 495 / (1.0324 - 0.19077 x log10(waist - neck) + 0.15456 x log10(height)) - 450. Female formula: 495 / (1.29579 - 0.35004 x log10(waist + hip - neck) + 0.22100 x log10(height)) - 450. Measurement technique can shift the output, so repeated measurements under similar conditions are more useful than a single reading.
Body Fat Categories and Fitness Classifications
Body fat categories differ between sexes because fat distribution and essential-fat needs differ. The calculator shows broad reference bands such as essential, athlete, fitness, average, and obese. These labels are not medical diagnoses and may not fit every body type, sport, age group, or clinical situation. If a result is unexpected, repeat the measurements and compare with waist, BMI, performance, and professional guidance when relevant.
Improving Body Composition Through Training and Nutrition
Reducing body fat while preserving or building muscle requires strategic combination of nutrition and exercise. Create a moderate caloric deficit of 300-500 calories below TDEE to promote fat loss while maintaining energy for training. Prioritize protein intake at 1.6-2.2g per kg bodyweight to support muscle protein synthesis and increase satiety. Incorporate resistance training three to four times weekly to stimulate muscle retention and boost metabolic rate. Add cardiovascular exercise for additional calorie burn and cardiovascular health benefits. Track body fat percentage monthly rather than weekly, as fluctuations in hydration and measurement technique can mask true progress. Combine body fat tracking with waist measurements, progress photos, and strength performance for comprehensive body composition assessment.