Body Fat Calculator: Understanding Your Body Composition
Body fat percentage is a more meaningful measure of health and fitness than weight alone. Our calculator provides three proven estimation methods: the US Navy Method, BMI-based estimation, and Relative Fat Mass (RFM). Each approach has strengths—the Navy method uses circumference measurements for accuracy, BMI-based is convenient but less precise, and RFM offers a modern research-based approach using just waist and height.
Understanding your body fat percentage helps you set realistic fitness goals, track progress beyond the scale, and assess health risks. Athletes might target 6-13% (men) or 14-20% (women), while healthy ranges extend to 17-25% for men and 24-31% for women. See our BMI Calculator and Calorie Calculator for related measurements.
The Three Calculation Methods
US Navy Method uses circumference measurements (waist, neck, height for men; waist, hip, neck, height for women) in a logarithmic formula. It's one of the most accurate non-laboratory methods, originally developed for military fitness assessment.
BMI-Based Estimation uses your BMI, age, and gender in a formula that approximates body fat. While convenient (no body measurements needed), it's less accurate for muscular individuals or extreme body types.
Relative Fat Mass (RFM) is a newer formula using height and waist circumference. Research suggests it correlates well with body fat measured by DXA scans, making it a simple yet reliable option.
Body Fat Categories Explained
Essential Fat: The minimum fat required for basic physical and mental health. Below this level is dangerous. Athletes: Competitive athletes often maintain this range, though it can be difficult to sustain. Fitness: A healthy, lean range achievable with regular exercise.
Average: Typical for adults with moderate activity. Obese: Elevated health risks including cardiovascular disease, diabetes, and joint problems. Track progress with our Ideal Weight Calculator.
FAQ
Which method is most accurate?
The Navy method is generally most accurate, followed by RFM. BMI-based is least accurate but requires no measurements. For precision, consider DEXA scans or professional calipers.
How do I measure correctly?
Measure waist at the narrowest point (usually at the navel), neck at the narrowest point below the Adam's apple, and hips at the widest point. Use a cloth tape measure and keep it level.