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A body shape index (ABSI) calculator

Short answer

A body shape index compares your waist with what is typical for your height and weight: ABSI = waist ÷ (BMI^(2/3) × height^(1/2)), in metres. A 40-year-old man at 175 cm and 75 kg with a 90 cm waist has an ABSI of 0.0807, a z score of -0.05 against US men his age. In the US adults it was built on, each 1-point higher z score went with 1.33 times the risk of death, on average.

Last reviewed 28 October 20261 published sourcesNot medical advice

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A body shape index (ABSI) calculator

For adults 18 and over. Keep the tape level around your waist and measure after breathing out normally.

Enter your age, waist, height and weight.

Runs entirely in your browser. Nothing you type is saved or sent anywhere.

Average ABSI by age and sex in US adults
Age	Men	Women
20	0.0773	0.0776
30	0.0795	0.0774
40	0.0809	0.0782
50	0.0826	0.0795
60	0.0844	0.0810
70	0.0859	0.0828
80	0.0871	0.0844

Smoothed means from the paper's supplementary Table S1 (NHANES 1999–2004), the values this calculator uses for z scores (Krakauer & Krakauer, 2012).

Where ABSI comes from

Krakauer and Krakauer built ABSI from 14,105 nonpregnant adults in the US NHANES 1999–2004 surveys, scaling waist circumference so it is nearly independent of height, weight and BMI. The sample average was 0.0808 ± 0.0053 (Krakauer & Krakauer, 2012).

Each z score uses the smoothed mean and standard deviation for one year of age and sex; people aged 85 and over share one reference row. Over an average follow-up of 4.8 years, the unadjusted hazard of death was 1.33 times higher per 1-point rise in ABSI z score (Krakauer & Krakauer, 2012).

Related measures

For simpler waist-based checks, try the waist-to-height ratio calculator or the body roundness index calculator.

Body changes, tracked over time

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Common questions

How is ABSI calculated?

ABSI = waist circumference ÷ (BMI^(2/3) × height^(1/2)), with waist and height in metres and weight in kilograms. Because BMI is in the formula, ABSI is built to be nearly independent of it.

What is a normal ABSI?

ABSI rises with age and differs by sex, so it is read as a z score against people of your age and sex. Across the whole US sample the average was 0.0808 with a standard deviation of 0.0053. A z score of 0 is exactly average.

What does a high ABSI z score mean?

In the study, each 1-point higher z score went with 1.33 times the hazard of death (95% CI 1.20–1.48) over follow-up. That is an average across thousands of people, not a personal prediction.

Sources

Figures on this page were checked against these publications on 28 October 2026.

Krakauer NY, Krakauer JC. A new body shape index predicts mortality hazard independently of body mass index. PLoS One. 2012;7(7):e39504. doi.org/10.1371/journal.pone.0039504

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