ABSI and Body Roundness Index Calculator (Waist-Based Risk Indices)

What this tool does

BMI cannot tell where fat sits, yet fat around the middle is the kind most linked to health risk. ABSI, proposed by Krakauer and Krakauer in 2012, scales the waist so that it is independent of BMI; it is then compared with the average for your age and sex, which needs reference tables this page does not hold, so use it as a number to track rather than a verdict. BRI, from Thomas and colleagues in 2013, models the body as an ellipse and returns a figure that rises as the waist grows relative to height, often somewhere between 1 and 10. Measure the waist at the same place each time, halfway between the lowest rib and the top of the hip bone.

Formula

ABSI = waist (m) ÷ (BMI^(2/3) × height (m)^(1/2)) · BRI = 364.2 − 365.5 × √(1 − (waist ÷ 2π)² ÷ (0.5 × height)²)

Variables

Worked example

Limitations

• This tool is informational only. It does not diagnose, treat or replace a qualified health professional. Speak to a doctor before making decisions about your health.
• The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.