How to Calculate Your Body Fat Percentage at Home

Body fat percentage is a more accurate indicator of health than BMI alone. It measures the proportion of your total weight that comes from fat tissue versus lean mass (muscle, bone, organs, and water). Two people with the same BMI can have very different body fat percentages and, therefore, different health profiles.

Tracking body fat percentage over time provides better feedback on your fitness and nutrition program than scale weight alone. If you are gaining muscle and losing fat, your weight may stay the same while your body composition improves dramatically.

One of the most accessible ways to estimate body fat is the US Navy Method, which uses body circumference measurements. For men, it requires neck and waist measurements. For women, it requires neck, waist, and hip measurements. The formula accounts for height and uses these circumferences to estimate fat percentage.

The formula for men is: %Fat = 495 / (1.0324 - 0.19077 × log(waist - neck) + 0.15456 × log(height)) - 450. For women, it adds hip measurement: %Fat = 495 / (1.29579 - 0.35004 × log(waist + hip - neck) + 0.22100 × log(height)) - 450. Our body fat calculator handles this automatically.

Essential body fat (needed for survival) is 2-5% for men and 10-13% for women. Athletes typically have 6-13% (men) and 14-20% (women). Fit individuals range from 14-17% (men) and 21-24% (women). Acceptable ranges go up to 25% (men) and 31% (women), while above these is considered obese.

Women naturally have higher essential fat due to childbearing requirements and hormonal differences. Body fat distribution also matters – visceral fat around organs is more dangerous than subcutaneous fat under the skin. Waist circumference is a good proxy for visceral fat risk.

The US Navy Method (circumference-based) is free and accessible but has a margin of error of about 3-4%. Skinfold calipers are inexpensive and accurate with proper technique. Bioelectrical impedance scales are convenient but vary in accuracy. DEXA scans are the gold standard but require specialised equipment.

For most people, consistent use of one method over time is more valuable than absolute accuracy. Track trends, not individual readings. Our body fat calculator uses the US Navy Method and provides a good starting point for monitoring your body composition.