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ABSI Calculator

Created by Joanna Michałowska, PhD candidate
Reviewed by Dominik Czernia, PhD, Jack Bowater and Łucja Zaborowska, MD, PhD candidate
Based on research by
Krakauer NY, Krakauer JC. A new body shape index predicts mortality hazard independently of body mass index.; PLoS One; July 2012
Last updated: Jan 18, 2024

The ABSI calculator estimates the risk of premature mortality based on the A Body Shape Index (ABSI). The ABSI formula requires only a few variables: age, sex, body height, body mass, and waist circumference.

The inclusion of the last measurement makes ABSI a better indicator of risk of mortality from excessive weight than the standard body mass index (BMI). Read the article below to find out more about the A Body Shape Index pros and cons and the ABSI formula! 🤓

A Body Shape Index (ABSI)

The A Body Shape Index has been developed by Nir and Jesse Krakauer from a sample of Americans in the National Health and Nutrition Examination Survey. The aim of the authors was to develop a formula that is based on waist circumference and is approximately independent (less dependent) of height, weight, and BMI. They have developed the A Body Shape Index that includes five variables:

  • Sex;
  • Age;
  • Weight;
  • Height; and
  • Waist circumference.

🙋 If you are interested in the more known BMI, visit our BMI calculator: with a few inputs and no time at all, you be able to calculate its value!

A Body Shape Index formula - ABSI formula and ABSI z score:


We present the ABSI formula below:



  • WC\mathrm{WC} – The waist circumference, expressed in m\mathrm{m};

  • height\mathrm{height} – Expressed in m\mathrm{m}; and

  • BMI\mathrm{BMI} – Expressed in kg/m2\mathrm{kg}/\mathrm{m^2}, and is calculated using the following formula:

BMI=weightheight2\qquad \mathrm{BMI}=\frac{\mathrm{weight}}{\mathrm{height}^2}


To estimate the risk of premature mortality, we can calculate the ABSI z score as follows:

ABSIz score ⁣= ⁣ABSIABSImeanABSISD\mathrm{ABSI}_{\text{z score}}\! =\! \frac{\mathrm{ABSI}-\mathrm{ABSI}_{\text{mean}}}{\mathrm{ABSI}_{\text{SD}}}


  • ABSIz score\mathrm{ABSI}_{\text{z score}} – Calculated based on the mean and standard deviations of ABSI calculated for the given age and sex;

  • ABSImean\mathrm{ABSI}_{\text{mean}} – The mean ABSI for the chosen age and sex; and

  • ABSISD\mathrm{ABSI}_{\text{SD}} – The standard deviation of the calculated ABSI for the chosen age and sex.

This calculator uses the gets its mean and standard deviation data for each age and sex bracket from the data available for the population of NHANES.

Based on the ABSI z score, the results are classified into five premature mortality risk levels:

ABSIz score\boldsymbol{\mathrm{ABSI}_{\text{z\ score}}}

Mortality risk


Very low

0.868-0.868 - 0.272-0.272


0.272-0.272 - +0.229+0.229


+0.229+0.229 - 0.7980.798



Very high

🙋 Our BAI calculator will explain to you another index used to calculate your fitness: the body adiposity index.

How to use A Body Shape Index (ABSI) calculator?

Using the ABSI calculator is very easy – just follow these steps:

  1. Choose your sex.
  2. Enter your age (the values must range from 2 to 85 years).
  3. Enter your height. Don't worry about the units – our ABSI calculator has a built-in length converter.
  4. Enter your weight. Again, don't worry about the units conversion.
  5. Input your waist circumference. It should be measured horizontally around the waist, at the level of your belly button.

That's all! In the "Results" section, you will be able to see your ABSI score, ABSI z score, and the interpretation of your result.

A Body Shape Index – pros and cons

The higher the ABSI, the higher the proportion of abdominal fat compared to other body parts. ABSI correlates only slightly with height, weight, and BMI, indicating that it is independent of other anthropometric variables in predicting mortality. It can also predict the risk of cardiovascular disease, cancer, and diabetes.

However, the risk calculated with the ABSI score is based only on the body model. Other factors that influence life expectancy (e.g., other illnesses) are not taken into account. We created our diabetes risk calculator and CVD risk calculator to give you a more comprehensive model to calculate those risks.


How do I calculate the ABSI z-score?

To calculate the ABSI z-score, first, you need to calculate the ABSI score:

  1. Multiply the individual's BMI (raised to power 2/3) by height (raised to the power 1/2), i.e., BMI2/3 × height1/2.
  2. Divide waist circumference by the result.

Then, you can calculate the ABSI z-score with the following steps:

  1. Subtract the individual's ABSI score from the mean score.
  2. Divide by standard deviation for age and gender.

Can the ABSI score be used to assess the risk of diabetes?

The ABSI score can be used to assess the risk of type 2 diabetes. The tool demonstrates good diagnostic performance — however, ABSI should be combined with other tools and health indicators to provide a comprehensive assessment.

What does it mean if my ABSI score is >0.798?

If your ABSI score exceeds 0.798, you may face an elevated risk of mortality and an increased likelihood of developing health issues, including cardiovascular disease, type 2 diabetes, and certain types of cancer.

What are similar tools to A Body Shape Index (ABSI)?

Several other tools use body measurements to evaluate the risk of health conditions, including diabetes and cardiovascular disease. Some of these tools include:

  • The Visceral Adiposity Index (VAI): This index is sex-specific and is often used to evaluate the degree of visceral adiposity and insulin sensitivity.
  • The Conicity Index (CI): This index is utilized to assess body fat distribution and obesity and has been used to evaluate the risk of cardiovascular disease.
Joanna Michałowska, PhD candidate
Waist circumference
ABSI z-score
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