A Body Shape Index Calculator
Calculate ABSI and ABSI z-score from age, sex, height, weight, and waist circumference for mortality risk.
Calculate A Body Shape Index (ABSI)
A Body Shape Index (ABSI) estimates body shape using waist circumference relative to height and BMI. Unlike BMI alone, ABSI emphasizes abdominal size and may highlight mortality risk patterns linked to central adiposity. This calculator returns ABSI, BMI, population expected ABSI, standard deviation, and an ABSI z-score with risk interpretation.
ABSI Formula
$$ABSI = \dfrac{WC}{\sqrt{height} \times BMI^{2/3}}$$
Waist circumference ($WC$) and height must use the same unit (meters in the formula). BMI is weight divided by height squared. The z-score compares your ABSI with age and sex adjusted population parameters.
How ABSI Differs From BMI
BMI tracks overall mass relative to height but does not distinguish central fat from muscle. ABSI adds waist size to capture abdominal distribution. Use it alongside other metrics such as the BMI Calculator and Body Fat Calculator for a fuller body composition picture.
Frequently Asked Questions
What is a normal ABSI z-score?
Z-scores near zero reflect average population risk. Negative z-scores suggest lower modeled mortality risk, while higher positive z-scores suggest greater modeled risk.
How should I measure waist circumference?
Measure at the narrowest point between the lower rib and top of the hip bone after normal breathing, keeping the tape horizontal and snug without compressing skin.
Does ABSI replace BMI?
No. ABSI complements BMI by emphasizing waist size. Many clinicians review both metrics together with blood pressure, lipids, and glucose.
Why does age affect the z-score?
Expected ABSI and its variability change across the lifespan. The z-score adjusts for age and sex using published regression coefficients.
Who should not rely on ABSI alone?
Athletes with large muscle mass, pregnant individuals, and people with abdominal devices or distention may need clinician guided assessment beyond a single index.
Related Tools
MPS Calculator
Working Days
Convert Bmp To Base64
Lego Brick House Calculator
Pie Chart Generator
IQ Percentile Calculator
Baudot Code
Sort Text Lines
Loss Given Default Calculator
Multifactorial Calculator
Coffee Footprint Calculator
VTT to Text Converter
TOML to YAML Converter
Ramp Slope Calculator
Create Symmetric List
Actual Cash Value
Validate UTF8
SWP Calculator
Numbers to Words Converter
Measurement Converter