How is the result calculated?
Using the "US Navy Method" equation, an anthropometric formula originally developed to assess soldiers' fitness in the field without equipment, based only on neck and waist circumference (plus hip for women) and height.
How accurate is this method compared to body fat measuring devices?
It's accurate to within roughly ±3-4% compared to precise lab measurement (like a DEXA scan), which is far more accurate than relying on BMI alone, since BMI doesn't distinguish between muscle and fat at all.
Why do women need a hip measurement while men don't?
Because fat distribution differs biologically between the sexes — in women, a significant portion of fat concentrates around the hips, so including this measurement improves estimate accuracy for them specifically, while the men's equation is more accurate using just neck and waist.
How do I measure my neck and waist correctly?
Neck: right below the Adam's apple (for men), or at the narrowest point (for women). Waist: at the navel for men, and at the narrowest part of the waist for women — without sucking in your stomach or pulling the tape tight. Hip (for women): at the widest point of the hips. Repeat each measurement twice and take the average to reduce error.
Is this result useful for tracking my exercise progress over time?
Yes, and this is one of its best uses — since it relies on simple body measurements that can easily be repeated roughly every two weeks to track changes in your body composition (not just your weight), a more accurate indicator than the scale alone while building muscle or losing fat.
