BMI & Body Composition Calculator
Calculate your BMI, body fat percentage, and lean mass to better understand your health
Understanding Body Composition
Body composition refers to the proportion of fat and non-fat mass (muscle, bone, and water) in your body. Unlike weight alone, body composition provides a clearer picture of your health by distinguishing between fat mass and lean mass.
This calculator uses the U.S. Navy method to estimate your body fat percentage based on measurements of your neck, waist, and (for women) hips. While not as precise as clinical methods like DEXA scans, it provides a reasonable approximation that can help you track changes over time.
Body Composition Calculator
How to Interpret Your Results
BMI (Body Mass Index): A general indicator of weight status based on height and weight. While useful for population studies, BMI doesn't distinguish between muscle and fat, so it has limitations for athletes or those with higher muscle mass.
Body Fat Percentage: The proportion of your total weight that is fat mass. Healthy ranges vary by gender, age, and fitness level:
- Men: 6-24% (Athletic: 6-13%, Fitness: 14-17%, Average: 18-24%, Obese: 25%+)
- Women: 14-31% (Athletic: 14-20%, Fitness: 21-24%, Average: 25-31%, Obese: 32%+)
Lean Mass: The weight of everything in your body except fat, including muscle, bones, organs, and water. Maintaining or increasing lean mass is important for metabolism, strength, and overall health, especially as you age.
Remember that these measurements are estimates and should be used as part of a broader health assessment. Consistent trends over time are often more valuable than any single measurement.