Body Fat Calculator Percentage Tool
Body Fat Calculator
Body Fat Percentage Calculator
Measure below the larynx
At navel level
The body fat calculator estimates your body fat percentage using the U.S. Navy circumference method. It measures neck, waist, and hip (for women) to estimate the proportion of your body weight that is fat rather than lean mass.
U.S. Navy Body Fat Formula
Men: %BF = 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76 Women: %BF = 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387
All measurements in inches. Take waist at navel for men, at narrowest point for women. Take neck at its narrowest. Women also measure hips at the widest point.
Body Fat Percentage Classification
| Category | Men | Women |
|---|---|---|
| Essential fat | 2-5% | 10-13% |
| Athletes | 6-13% | 14-20% |
| Fitness | 14-17% | 21-24% |
| Average | 18-24% | 25-31% |
| Obese | 25%+ | 32%+ |
Body Fat vs. BMI
BMI uses only weight and height. Body fat percentage directly measures what fraction of your mass is fat. Two people with the same BMI can have very different body fat percentages. A muscular person may have a high BMI with 10% body fat. An inactive person may have a normal BMI with 30% body fat. Body fat percentage is more meaningful for health and fitness goals.
How to Take Accurate Measurements
Measure in the morning before eating. Stand straight and breathe normally. Do not suck in or flex. Use a flexible, non-stretch tape. Take each measurement twice and average if they differ by more than 0.25 inches. Waist for men is at the navel. Waist for women is at the narrowest point, usually 1-2 inches above the navel.
Frequently Asked Questions
What is a healthy body fat percentage?⌄
For men, 14-17% is fitness level and 18-24% is average. For women, 21-24% is fitness level and 25-31% is average. Below 6% for men or 13% for women is in the essential fat range and is below healthy levels for most people. Athletes often sit at 6-13% (men) or 14-20% (women).
How accurate is the body fat calculator?⌄
The Navy circumference method has a margin of error of roughly 3-4% compared to DEXA scans (considered the gold standard). It is more accurate than BMI for estimating body composition, especially for muscular individuals. Measurement consistency matters more than absolute accuracy for tracking progress over time.
How can I lower my body fat percentage?⌄
Create a calorie deficit through diet, increase resistance training to preserve muscle mass, and maintain adequate protein intake (1.6-2.2g per kg). Fat loss of 0.5-1% body fat per month is sustainable. Rapid fat loss causes muscle loss, which reduces the lean tissue that makes body fat percentage meaningful.
What body fat percentage is considered obese?⌄
Clinical obesity by body fat is defined as above 25% for men and above 32% for women by most medical references. This correlates roughly with a BMI of 30, though the relationship varies based on muscle mass and distribution.
Is 20% body fat healthy for a man?⌄
20% body fat for a man falls in the average range. It is not a health risk on its own, but trending toward the high end of average. 14-17% is considered a fitness level for men. The more important factor is whether body fat is stable, whether visceral (abdominal) fat is high, and other metabolic markers.