ABSI Calculator
Calculate your A Body Shape Index (ABSI) to assess health risk based on waist circumference relative to BMI and height.
Enter Your Values
Enter your values and press Calculate: you will get the result, its method, the inputs used and confidence, plus copy, print and share options.
How this calculator works
A Body Shape Indexv1.0.0
ABSI = waist / (BMI^(2/3) × height^(1/2)); isolates abdominal shape from overall size.
- Applies to
- Adults
- Assumptions
- Accurate waist and height measures
- Limitations
- Interpretation requires population reference values
- Output
- index
- Last reviewed
- 2026-06-01
Evidence Sources & Literature
- PLoS ONE. An anthropometric index based on abdominal height, the body shape index (ABSI). PLoS ONE, 2012. doi:10.1371/journal.pone.0039504.
About the ABSI Calculator
ABSI (a body shape index) is a measure designed to assess the health risk linked specifically to your waist size, adjusted for your height and weight. The reason it exists is clever: a large waist is riskier in a smaller person than the same waist on a larger person, and ABSI tries to account for that, isolating the risk that comes from central fat rather than overall size. This calculator computes your ABSI from your waist, height and weight.
ABSI is more of a research-oriented measure than an everyday one, so I present it as a complement to simpler tools. Its value is that it zeroes in on abdominal fat, which is the fat most tied to health risk, and does so in a way that BMI alone cannot.
The problem ABSI solves
Waist circumference is a good risk marker, but on its own it does not account for how big a person is overall. ABSI adjusts your waist measurement for your height and weight, so it captures the part of your shape that is specifically about carrying fat around the middle, independent of how tall or heavy you are. In research, a higher ABSI has been associated with higher health risk even when BMI looks normal.
How it differs from BMI
BMI can entirely miss central fat, someone can have a normal BMI yet carry risky abdominal fat (sometimes called normal-weight obesity). ABSI is built precisely to flag that situation, because it foregrounds the waist. That makes it a useful complement: BMI for overall size, ABSI for the shape and fat-distribution piece that BMI cannot see.
Interpreting your result
ABSI is usually interpreted relative to averages for your age and sex rather than against a single fixed number, and the calculator gives you the computed value. A higher-than-average ABSI suggests more risk-associated central fat. Because it is a research measure, I would not treat any single reading as a diagnosis, but a consistently high value is a reasonable prompt to look at your waist and overall habits, and to mention it to your clinician.
What to do with it
As with the other waist-based measures, the encouraging news is that the same lifestyle steps help: regular movement, a whole-food diet rich in fiber, limiting ultra-processed foods and added sugars, decent sleep and stress management all tend to reduce abdominal fat. Accurate, consistent waist measurement is essential for ABSI to mean anything, so measure at the same spot each time.
Dietitian Insight: A Body Shape Index standardizes waist circumference relative to height and weight to assess abdominal adiposity risk independent of BMI. Explore our clinical comparison of body shape indices vs standard BMI, and compare findings with our Body Roundness Index tool.
Sources & method
This calculator uses established, peer-reviewed formulas and reference ranges from recognized health and nutrition authorities. Results are estimates for general education, not a medical diagnosis. For decisions about your health, consult a qualified clinician. Reviewed by Macro & Meals Editorial Team, Content editor.
Frequently Asked Questions
What is ABSI?
ABSI (a body shape index) assesses the health risk linked specifically to your waist size, adjusted for your height and weight. It isolates the risk from central (abdominal) fat rather than overall body size, which is why a large waist on a smaller person scores differently from the same waist on a larger person.
How is ABSI different from BMI?
BMI measures overall size and can entirely miss central fat, so someone with a normal BMI can still carry risky abdominal fat. ABSI is built to flag exactly that by foregrounding the waist. The two work well together: BMI for size, ABSI for fat distribution.
How do I interpret my ABSI score?
ABSI is usually read relative to averages for your age and sex rather than a single fixed cut-off. A higher-than-average value suggests more risk-associated central fat. Because it is a research-oriented measure, treat a high reading as a prompt to look at your habits and consult your clinician, not as a diagnosis.
How can I lower my ABSI?
Reducing abdominal fat is the goal, and the familiar habits help: regular activity, a fiber-rich whole-food diet, limiting ultra-processed foods and added sugars, good sleep and stress management. Measure your waist accurately and consistently so the score reflects real change.
Explore More Categories
