ABSI Calculator
Calculate A Body Shape Index (ABSI) — a measure of central obesity that predicts mortality risk independently of BMI.
What is ABSI?
A Body Shape Index (ABSI) was developed by Krakauer & Krakauer in 2012 to overcome the limitations of BMI by including waist circumference. It is one of the few simple anthropometric indices that predicts mortality independently of BMI, age, sex, weight and height. A higher ABSI indicates more central (abdominal) fat for a given body size, which is strongly linked to cardiometabolic disease.
Unlike BMI, ABSI penalises a thick waist even in people whose total weight is in the normal range. That makes it especially useful for adults who appear lean by the scale but carry excess visceral fat — the so-called "thin-fat" phenotype.
How is it calculated?
The ABSI formula is: ABSI = waist (m) / [BMI2/3 × height (m)1/2] where BMI is computed from weight (kg) and height (m). Population-average ABSI values rise with age; ABSI z-scores allow comparison against a same-age cohort. There is no universally agreed cut-off, but values above the 80th percentile for your age group are linked with markedly higher mortality risk.
Frequently Asked Questions
- Is ABSI better than BMI?
- ABSI complements BMI by capturing central fat distribution. Use both together for a fuller picture.
- What is a healthy ABSI?
- ABSI rises with age. Values around the population mean for your age band are considered average; those in the top 20% indicate elevated mortality risk.
- Where do I measure my waist?
- At the level of the navel, after a normal exhalation, with the tape snug but not compressing the skin.
- Can children use ABSI?
- ABSI was developed for adults. Pediatric body composition uses different age- and sex-specific tools.