How ABSI is calculated
A Body Shape Index adjusts waist circumference for the fact that taller, heavier people naturally have bigger waists. Unlike BMI, which only weighs total mass, ABSI targets central (abdominal) fat — a stronger predictor of mortality risk in the original study.
- waist — waist circumference in meters (cm ÷ 100)
- height — height in meters (cm ÷ 100)
- BMI — weight (kg) / height (m)²
More detail
Why ABSI exists alongside BMI
Two people can share the same BMI yet carry fat very differently — one around the waist, one around the hips and thighs. Krakauer & Krakauer (2012) introduced ABSI specifically to isolate the waist-circumference component, after finding it predicted mortality hazard independently of BMI across a large US population sample (NHANES).
Reading the raw number
ABSI values for adults typically fall between about 0.070 and 0.090 — the index is deliberately near-independent of BMI and height by construction, so a raw value alone is hard to interpret without a reference population. Clinical use converts it to an age- and sex-adjusted z-score; this calculator reports the raw index used in that formula.
Practical tip. Measure your waist at the navel level, standing, after a normal exhale, without pulling the tape tight. Small measurement inconsistencies shift ABSI more than they shift BMI, since ABSI is built directly from the waist number.
Frequently asked questions
What does ABSI measure that BMI doesn't?
BMI only relates total weight to height, so it can't distinguish someone carrying fat around the waist from someone carrying it around the hips. ABSI isolates the waist-circumference component after adjusting for BMI and height, targeting abdominal fat specifically — enter your waist, height, and weight above to get your value.
What's a typical ABSI value?
Adult ABSI values typically range roughly 0.070–0.090, for example about 0.077 for a 170cm, 65kg person with an 80cm waist. Because the index is designed to be near-independent of BMI and height, comparing your raw value against age- and sex-matched population data (a z-score) is more meaningful than the number alone.
Where does the ABSI formula come from?
Krakauer NY and Krakauer JC introduced it in 'A New Body Shape Index Predicts Mortality Hazard Independently of Body Mass Index' (PLoS ONE, 2012), analyzing NHANES data to show waist circumference — after removing its correlation with BMI and height — independently predicted mortality risk.