Body Adiposity Index (BAI) Calculator

Body Adiposity Index (BAI) Calculator for Endocrinology. The index was proposed as an estimate of adiposity. It is not a direct body-fat measurement, and the tool no longer applies male fitness bands to every person.

For shared guidance on choosing a tool and documenting results, read the clinical calculator workflow.

How this calculator works

BAI = hip circumference in cm divided by height in meters to the power 1.5, minus 18. This is the Bergman anthropometric index, not the RFM waist-to-height equation.

When to use this calculator

Explore the index while preserving the original measurement method. Record hip circumference rather than substituting waist circumference, since using the wrong anatomical site changes the modeled quantity.

Inputs used

  • Hip circumference in cm
  • Height in cm, converted internally to meters

Clinical interpretation

The index was proposed as an estimate of adiposity. It is not a direct body-fat measurement, and the tool no longer applies male fitness bands to every person.

Worked example

At hip circumference 100 cm and height 180 cm, the calculation is 100 / 1.8^1.5 - 18, approximately 23.41. A ten-centimeter increase in hip at the same height raises the index by about 4.14.

Limitations and safety notes

The development and validation populations do not establish universal accuracy. Pregnancy, body-size extremes and measurement variability limit interpretation. Implausible results are rejected without inventing a zero-percent result.

Frequently asked questions

Is hip measurement interchangeable with waist measurement?

No. BAI uses hip circumference. RFM uses waist circumference and a different model.

References

  • https://pubmed.ncbi.nlm.nih.gov/21372804/
  • https://pmc.ncbi.nlm.nih.gov/articles/PMC3275633/

Editorial review and citation methodology

Maintained by the Quick Medical Calculator Editorial Team. Content record date: September 9, 2026. A content date is not evidence of independent clinical review. Individual clinical sign-off is not recorded on this page.

  • Prefer original validation studies for scoring systems and prediction tools.
  • Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
  • Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.

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