It uses waist circumference in meters, BMI, and height in meters. BMI is calculated from the entered height and weight.

How should I measure my waist?

Supply a waist value measured consistently. Keep the same measurement approach when comparing results.

Why is there no risk category?

Interpreting ABSI against a population requires reference values matched to age, sex, and population. An ABSI number alone does not support a personal mortality or disease-risk category.

Does ABSI diagnose a health condition?

No. ABSI is a research measure, not a diagnosis. Waist measurement, blood pressure, laboratory results, symptoms, medical history, and clinical context may all matter.

A Body Shape Index Calculator

ABSI is a research body-shape index built from waist circumference, height, and weight. Use it when you need the reproducible raw index, not a diagnosis or a personal risk category. Keep the three measurements from the same measurement session.

Entering the measurements

The starting values are 170 cm for height, 70 kg for weight, and 80 cm for waist circumference. Height and weight are used to find BMI; waist is first converted from centimeters to meters. Supply a consistently measured waist value, and keep the same measurement approach when comparing dates.

The supported ranges are 50–250 cm for height, 10–300 kg for weight, and 30–200 cm for waist. A result outside those entry ranges is not produced.

Method and example

First:

$\text{BMI}=\frac{\text{weight (kg)}}{\text{height (m)}^2}$

Then:

$\text{ABSI}=\frac{\text{waist (m)}}{\text{BMI}^{2/3}\times\text{height (m)}^{1/2}}$

For 170 cm, 70 kg, and an 80 cm waist, BMI is 70/1.70^2=24.22 kg/m². Substitution gives:

$\text{ABSI}=\frac{0.80}{24.22^{2/3}\times1.70^{1/2}}\approx0.0733$

The result is shown to four decimal places and BMI to one. If only the waist changes to 100 cm, the result becomes 0.0916. That comparison shows how this index responds to waist while height and weight stay fixed; it does not establish that either value is healthy or unhealthy.

A useful comparison workflow

Recheck all three measurements before comparing two ABSI values.
Keep the waist measurement approach unchanged.
Record the unrounded measurements, date, and raw ABSI together.
Use waist-to-height ratio for the simpler waist-versus-height task, or BMI for the weight-versus-height task. The measures answer different questions and are not interchangeable.

Interpretation limits

The original research evaluated population associations. An ABSI z-score needs reference means and standard deviations matched to age, sex, and comparison population. The ABSI number alone does not justify an individualized mortality or disease-risk label.

ABSI cannot distinguish muscle, fat, pregnancy-related change, fluid retention, or other body-composition differences. Treat it as one recorded research measure alongside the broader context a qualified healthcare professional would use.

Sources

Krakauer NY and Krakauer JC, A new body shape index predicts mortality hazard independently of body mass index — original equation and population-research context.
CDC, About Adult BMI — adult BMI formula and screening limitations.