Health

Body Roundness Index (BRI) Calculator

Calculate your Body Roundness Index (BRI) from waist circumference and height. A body-shape metric that estimates central fat and visceral adiposity.

Body Roundness Index (BRI) Calculator

Waist Circumference (cm)

Height (cm)

Method

How this calculator works

BRI = 364.2 − 365.5 × √(1 − ((waist_m ÷ (2π))² ÷ (0.5 × height_m)²)), where waist and height are converted from centimeters to meters.

Enter your waist circumference in centimeters.
Enter your height in centimeters.
The calculator converts both to meters and computes an eccentricity term from the waist and height.
It applies the BRI formula to return a single roundness score, guarding the square-root term against invalid values.

Examples

Worked examples

Real numbers, end-to-end results.

Waist 85 cm, Height 175 cm

BRI ≈ 3.87

A moderate, relatively lean body shape.

Waist 110 cm, Height 170 cm

BRI ≈ 7.66

A rounder shape indicating higher central fat.

Use cases

When to use it

Estimating visceral fat and body-shape risk without a body scan
Complementing BMI and waist-to-height ratio in health screening
Tracking waistline-driven body-shape changes over time
Research and population health assessments of central adiposity

Disclaimer: This calculator provides estimates for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for decisions affecting your health. Results depend on the accuracy of inputs provided.

FAQ

Frequently asked questions

What is the Body Roundness Index (BRI)?

The Body Roundness Index is a measure of body shape that uses waist circumference and height to estimate how 'round' the body is. A higher BRI reflects a rounder shape and typically more visceral (abdominal) fat.

What is a typical BRI value?

BRI values usually fall between about 1 and 16. Lower values indicate a leaner, more elongated body shape, while higher values indicate a rounder shape often associated with greater central fat.

How is BRI different from BMI?

BMI uses weight and height, while BRI uses waist circumference and height. Because BRI focuses on the waistline, it is designed to better capture central-fat distribution and body roundness rather than overall mass.

How do I measure my waist for BRI?

Measure around the narrowest part of your torso, between the lowest rib and the top of the hip bone, after breathing out normally. Use the same unit (centimeters) as your height for a valid result.

Is a lower BRI always better?

Generally a moderate BRI is favorable, and very high values are linked with higher health risk. However, BRI is a screening estimate, so interpret it alongside other measures and professional advice.