What measurements does BRI use?

The original geometric equation uses height and waist circumference in the same unit. This calculator converts centimeters or inches before calculating the dimensionless index.

Is BRI a direct visceral-fat measurement?

No. BRI is an anthropometric model associated with body-fat and visceral-adipose measures in research. It is not DXA, CT, MRI, BIA, or another direct measurement.

Is there one universal BRI threshold?

No. Proposed research thresholds and distributions vary across age, sex, ethnicity, population, and outcome. This page reports the index without assigning a disease or treatment category.

Educational reference only. Not a diagnostic tool. See full disclaimer.

GeneralBody Roundness Index

Body Roundness Index Calculator

Calculate Body Roundness Index from height and waist circumference.

Content updated: July 18, 2026View sources

Height

Waist circumference

Body Roundness Index

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Geometric anthropometric estimate; no disease category is assigned

Normalized height: — cm · waist: — cm

About

Body Roundness Index (BRI) is a geometric anthropometric index derived from height and waist circumference. It estimates body shape for population research and is not a direct measurement of body fat or visceral adipose tissue.

Formula

BRI = 364.2 − 365.5 × √[1 − ((waist ÷ 2π)² ÷ (0.5 × height)²)]

Height and waist must first use the same length unit

Interpretation

What the result represents: A dimensionless index derived from an elliptical model of body geometry.

Input units: Enter both height and waist in centimeters or both in inches; the calculator normalizes them before applying the equation.

Worked example: Height 170 cm and waist 90 cm gives a BRI of approximately 3.93. Equivalent inch inputs give the same result.

Applicable population: Primarily adult anthropometric research; study distributions vary by age, sex, ethnicity, and population.

Interpretation limitations: BRI is not DXA, CT, MRI, BIA, or direct body-composition testing. It does not independently establish obesity, visceral fat, or metabolic disease and is not a treatment target.

References

FAQ

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Disclaimer

Educational and informational reference only. Not intended to replace professional medical advice, diagnosis, treatment, or independent verification.