Body-fat calculator
Estimate body-fat percentage using height, weight, waist, neck and hip measurements with metric or US units.
Estimate body-fat percentage
Use consistent tape measurements at the same locations. The circumference method is useful for trends but less accurate than clinical methods.
Your estimate
| Body-fat estimate | — |
| Lean body mass | — |
| Fat mass | — |
| Waist-to-height ratio | — |
Change any input to update the estimate.
How to improve repeatability
- Measure at the same time of day.
- Keep the tape level and snug without compressing skin.
- Take two or three readings and use the average.
- Track monthly rather than reacting to tiny changes.
What lean body mass means
Lean body mass includes muscle, organs, bone and body water. It is not the same as skeletal muscle. The estimate can help set broad protein or progress goals, but it should not be treated as a clinical scan.
Use waist trends too
Waist circumference and waist-to-height ratio can provide useful context alongside weight and strength performance. A single body-fat result is less useful than a consistent trend.
Frequently asked questions
How accurate is a tape-measure body-fat calculator?
It can be useful for consistent trend tracking, but measurement technique and body shape can create several percentage points of error.
Where should I measure waist?
Use the same anatomical location and tension each time. Follow the calculator method consistently rather than switching positions.
Why is hip required for women?
The selected circumference equation includes hip measurement in the female formula.
Is body-fat percentage better than BMI?
They answer different questions. BMI screens weight relative to height; circumference estimates attempt to describe body composition but also have error.
Method and sources
EKCal provides planning estimates, not diagnosis or treatment. Results should be checked against real-world trends and adjusted gradually.