Free body fat estimator
Body fat percentage is a far more reliable indicator than weight or BMI for evaluating your body composition. This calculator uses the US Navy method, scientifically validated, which only requires a tape measure.
Below Adam's apple
At navel
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Try for freeWhy know your body fat percentage
Weight alone says nothing about your body composition. Two people at the same weight can have radically different physiques depending on their muscle-to-fat ratio. Knowing your body fat % lets you adjust nutrition and training with precision, track real progress (fat loss vs muscle loss), and compare yourself to health benchmarks.
How to take measurements
- 1Measure your height barefoot
- 2Measure neck circumference just below the Adam's apple
- 3Measure waist at navel level (relaxed)
- 4For women: measure hip circumference at the widest point
- 5Enter the values and discover your estimate
Tips for accurate measurements
- •Always measure at the same time (ideally morning, fasted)
- •Use a soft tape measure, directly on skin
- •Don't suck in your stomach when measuring waist
- •Take 2-3 measurements and average them
- •Compare your results over time, not in absolute terms
Frequently asked questions
Yes, it has a 1-3% margin of error compared to DEXA scans. It's the most accurate method accessible without specialized equipment.
BMI doesn't differentiate between muscle and fat. A bodybuilder would be "obese" by BMI standards. Body fat % is a much more relevant indicator.
For men: 10-17% (fitness), 18-24% (average). For women: 18-24% (fitness), 25-31% (average). Athletes can go lower.
Every 2-4 weeks. Body composition changes slowly. More frequent measurements can be demotivating due to natural fluctuations.