ABSI Calculator

Estimate A Body Shape Index (ABSI) from your weight, height, and waist circumference — a marker of abdominal fat that BMI alone can miss.

Quick Facts

Formula
ABSI = waist ÷ (BMI^2/3 × √height)
All lengths in meters. A higher value means more central fat for the same BMI and height.

Your Results

Calculated
A Body Shape Index (ABSI)
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waist ÷ (BMI^2/3 × √height)
Body Mass Index (BMI)
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weight ÷ height²
Waist-to-height ratio
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waist ÷ height
Central-fat category
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From waist-to-height ratio

Ready

Enter your weight, height, and waist, then calculate.

Understanding your ABSI result

A Body Shape Index (ABSI) turns three simple measurements — weight, height, and waist circumference — into a single number that captures how much of your body sits around the middle. It was introduced in 2012 to address a known blind spot in BMI: two people can share the same BMI yet carry fat very differently, and abdominal fat is the type most closely tied to metabolic and cardiovascular risk.

The formula

ABSI is defined with every length in meters and BMI in kg/m²:

  • ABSI = waist ÷ (BMI2/3 × height1/2), where BMI = weight ÷ height².
  • Waist and height are converted from centimeters to meters (divide by 100) before the calculation.
  • A typical adult ABSI lands near 0.07 to 0.09. The exact value matters less than how it compares over time, or to people of similar age and sex.

Because ABSI divides waist by BMI and height, it isolates the part of your waist size that is not already explained by overall body size. A higher ABSI means your waist is larger than expected for your BMI and height — a marker of central (abdominal) fat.

How to measure your waist

Measure at the level of the navel, or midway between the lowest rib and the top of the hip bone, with the tape snug but not compressing the skin. Take the reading at the end of a normal breath out, and use the same landmark each time so your numbers stay comparable.

Two companion numbers

  • BMI tells you about overall weight for height, but not where fat sits.
  • Waist-to-height ratio (waist ÷ height) is an easy sanity check: keeping your waist under half your height — a ratio below 0.5 — is a widely used healthy target for adults.

What to do with this number

Treat ABSI as one screening signal among many, alongside blood pressure, blood sugar, cholesterol, fitness, and how you feel. A single reading is a snapshot; the trend over months matters more. If your waist measurement or ABSI concerns you, discuss it with a healthcare provider rather than acting on the number alone.

Frequently Asked Questions

What is A Body Shape Index (ABSI)?
ABSI, short for A Body Shape Index, was introduced in 2012 as a measure of abdominal fat. It is calculated as waist circumference divided by BMI to the two-thirds power times the square root of height, with all lengths in meters. A higher ABSI means more central fat for a given BMI and height.
How is ABSI different from BMI?
BMI compares weight to height but cannot show where fat sits on the body. ABSI adjusts waist circumference for BMI and height, so it isolates abdominal fat. Two people with identical BMI can have very different ABSI values, because ABSI was designed to flag central-fat risk that BMI alone misses.
How do I measure my waist for ABSI?
Measure at the level of the navel, or midway between the lowest rib and the top of the hip bone, with the tape snug but not compressing the skin, at the end of a normal breath out. Use the same landmark every time so your readings stay comparable.
Is an ABSI result a medical diagnosis?
No. ABSI is a population-based screening metric, not a diagnosis. Use it as one signal alongside blood pressure, blood markers, and fitness, and discuss any concerns with a healthcare provider rather than acting on the number alone.

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