A Body Shape Index (ABSI) Calculator
Calculate A Body Shape Index (ABSI) from waist, weight and height — a waist measure adjusted for BMI and height.
How to use this tool
- Measure your waist at the navel in centimetres.
- Enter your weight in kilograms.
- Enter your height in centimetres.
- Read your ABSI alongside the BMI used in the formula.
A Body Shape Index (ABSI) calculator measures whether your waist is larger than expected for your height and weight — a body-size-adjusted marker of abdominal fat that complements BMI.
Formula
ABSI = waist (m) ÷ (BMI2/3 × height (m)1/2)
where BMI = weight (kg) ÷ height (m)2. Waist and height are in metres. ABSI isolates the part of waist size that is not already explained by overall body size.
How it works
A Body Shape Index (ABSI) was developed by Nir and Jesse Krakauer and published in PLOS ONE (2012). It rescales waist circumference by BMI and height so that, statistically, ABSI is nearly independent of overall body size. A high ABSI means the waist is larger than expected for a person's height and weight, which in the original cohort was linked with higher mortality risk even at normal BMI.
ABSI values are small decimals (around 0.07–0.09 for adults) and are most informative when compared with age- and sex-specific reference data rather than read in isolation. We display the BMI used in the calculation for transparency.
This calculator is provided for general information and education only and is not medical advice. Body-shape indices are screening estimates, not diagnoses. Always consult a qualified healthcare professional before making decisions about your health.
Worked example
Waist 80 cm, weight 70 kg, height 175 cm
- Convert to metres: waist = 0.80 m, height = 1.75 m
- BMI = 70 ÷ 1.752 = 70 ÷ 3.0625 = 22.857
- BMI2/3 = 22.8572/3 = 8.05445
- height1/2 = √1.75 = 1.322876
- Denominator = 8.05445 × 1.322876 = 10.6549
- ABSI = 0.80 ÷ 10.6549 = 0.075086
- Round to four decimals = 0.0751
A Body Shape Index = 0.0751
ABSI — example values across body shapes (height 175 cm)
| Waist (cm) | Weight (kg) | BMI | ABSI |
|---|---|---|---|
| 75 | 70 | 22.86 | 0.0704 |
| 80 | 70 | 22.86 | 0.0751 |
| 90 | 80 | 26.12 | 0.0773 |
| 100 | 90 | 29.39 | 0.0794 |
Key terms
- A Body Shape Index (ABSI)
- A waist-based index rescaled by BMI and height so it is largely independent of overall body size and instead captures abdominal shape.
- BMI
- Body Mass Index, weight in kilograms divided by height in metres squared; used inside the ABSI formula.
- Visceral fat
- Fat stored deep in the abdomen around the organs; a high ABSI is associated with greater visceral fat for a given body size.
Frequently asked questions
- What is a good ABSI value?
- ABSI is interpreted against age- and sex-specific norms rather than a single cut-off. A lower ABSI means a smaller waist relative to your body size; values typically sit between about 0.07 and 0.09 in adults.
- Why is ABSI such a small number?
- The formula divides metres of waist by BMI and height terms, which produces small decimal values. The magnitude is normal — only the relative value matters.
- How is ABSI different from BMI?
- BMI reflects overall mass for height; ABSI adds waist circumference and is designed to be independent of BMI, so it flags abdominal shape that BMI alone misses.