The ABSI Calculator uses measurements from your body to calculate you 'A Body Shape Index' or ABSI.
Researchers at City College of New York developed the 'A Body Shape Index' formula. They took took data from over 14,000 non-pregnant adults, did some calculations. Comparing them with death rates for the same group, they found some interesting results. High death rates were found with both low and high BMI, but the ABSI calculation predicted premature death regardless of other factors like age, sex, ethnicity, and smoking.
ABSI measures the ratio of your waist-to-height ratio versus your weight-to-height ratio (used to determine yout body mass index).
You will need your waist circumference in cm, your height in cm, and your weight in kg.
From "New Body Shape Index Predicts Mortality Hazard Independently of Body Mass Index" by Nir Y. Krakauer and Jesse C. Krakauer:
"Obesity, typically quantified in terms of Body Mass Index (BMI) exceeding threshold values, is considered a leading cause of premature death worldwide. For given body size (BMI), it is recognized that risk is also affected by body shape, particularly as a marker of abdominal fat deposits. Waist circumference (WC) is used as a risk indicator supplementary to BMI, but the high correlation of WC with BMI makes it hard to isolate the added value of WC."