Your body fat

Find out your body composition from circumference measurements.

cm
kg
cm
cm
cm
26.9%
Healthy
Fat mass
17.2 kg
Lean (LBM)
46.8 kg
Ideal range 21–33% · you're in the ideal range
Info

What Is Body Fat Percentage?

Body fat percentage is the value showing what portion of your total body weight is fat tissue. The rest is lean body mass (LBM): muscle, bone, water and organs.

This ratio reveals what weight alone cannot: of two people at the same weight, one may be more muscular and the other fatter. So it is more telling than weight for understanding body composition.

Calxin estimates this ratio with the U.S. Navy method, evaluating neck, waist and (for women) hip circumference together with height. No device is needed — a tape measure is enough. The healthy range varies by sex.

Method

How Is Body Fat Percentage Calculated?

Body fat percentage shows what portion of your total weight is fat; the rest is lean mass (muscle, bone, water, organs).

Calxin uses the U.S. Navy circumference method. Neck and waist (plus hip for women) are evaluated together with height:

Male: Fat% = 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 30.30
Female: Fat% = 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 104.912

All measurements are in centimetres and the logarithm is base 10.

Accuracy depends on measuring at the correct points: the neck just below the larynx, the waist at the narrowest point, and the hip at the widest point.

This circumference-based method is practical but produces an estimate. Calipers, bioelectrical impedance and especially a DEXA scan give more precise results; DEXA is considered the gold standard in this field.