Body Fat Calculator
Enter gender, height, weight, neck and waist circumference to calculate body fat percentage.
Body Fat Guide
Uses the U.S. Navy formula. Male: 86.010รlog10(waistโneck)โ70.041รlog10(height)+36.76, Female: 163.205รlog10(waist+hipโneck)โ97.684รlog10(height)โ78.387
Worked Examples
A man with a 90 cm waist and 38 cm neck at 180 cm comes out near 20 % body fat, inside the healthy range.
A woman with an 80 cm waist, 95 cm hips and 32 cm neck at 165 cm lands near 30 %, the upper end of the acceptable range.
How Accurate Is a Tape Estimate?
The Navy formula is accurate to about 3-4 percentage points compared with DEXA, and it depends on measuring at the right landmarks with the tape level. It assumes an average build, so it is less reliable for very muscular people, during pregnancy and in older adults with reduced muscle mass.
Frequently Asked Questions
- What is a healthy body fat percentage?
- Roughly 10-20 % for men and 18-28 % for women. Athletes sit lower, and the essential minimum is about 2-5 % for men and 10-13 % for women.
- Is BMI or body fat better?
- BMI cannot tell muscle from fat, so a muscular athlete may look obese on it. Body fat percentage is more informative, but BMI is still useful at population level.
- Why does the result differ from my smart scale?
- Scales use bioelectrical impedance, which swings with hydration, food and time of day. Tape methods and DEXA are less sensitive to those factors.