Estimate body fat percentage using the US Navy method or BMI formula. Includes body composition breakdown.
What Is Body Fat Calculator?
A body fat calculator estimates the percentage of your body weight that is fat using body measurements and established formulas (typically the US Navy method). Unlike BMI, which only considers height and weight, body fat percentage distinguishes between fat mass and lean mass (muscle, bone, organs, water), giving a more accurate picture of body composition.
Healthy body fat ranges differ by gender: roughly 10–20% for men and 18–28% for women. Athletes may have lower percentages, while essential fat (the minimum needed for health) is about 2–5% for men and 10–13% for women. This calculator uses simple body measurements — no equipment required.
How to Use This Tool
Enter your gender, height and weight.
Measure and enter your waist circumference (at navel level).
For men: also measure neck circumference. For women: also measure hip circumference.
View your estimated body fat percentage and category.
See your lean mass and fat mass breakdown.
Tips & Best Practices
Measure consistently — same time of day, same conditions — for the most reliable tracking over time.
The US Navy formula is an estimate — DEXA scans and hydrostatic weighing are more accurate but require equipment.
Waist-to-hip ratio is another useful metric for health risk assessment.
Body fat percentage is more meaningful than weight alone — you can gain muscle while losing fat, keeping weight the same but improving health.
Common Use Cases
Estimating body fat percentage without specialised equipment.
Tracking body composition changes during fitness programmes.
Getting a more nuanced health assessment than BMI alone.
Setting realistic body composition goals for fitness training.
Frequently Asked Questions
Which method is more accurate?
The US Navy method using waist, neck (and hip for women) measurements is more accurate than BMI-based estimation.