Calculators · Endocrinology · Formula

HOMA-IR and HOMA-%B (Matthews 1985 approximation)

Also called HOMA, homeostasis model assessment, insulin resistance index

Insulin resistance and β-cell function from fasting glucose and insulin.

µU/mL (mU/L)

Fill 2 more fields to see the result.

Formula and scoring

HOMA-IR = fasting insulin (µU/mL) × fasting glucose (mmol/L) ÷ 22.5. HOMA-%B = 20 × insulin ÷ (glucose − 3.5).

Exam and ward pearls

  • HOMA-IR correlated with the euglycaemic clamp (Rs 0.88) in the original paper.
  • Best for cohorts and trends; a single value in one person is imprecise (CV about 31%).

When not to rely on it

  • These are the 1985 approximation formulae; the HOMA computer model gives different numbers.
  • Needs steady-state fasting values; insulin assays differ between laboratories.

Source

  1. Matthews DR, Hosker JP, Rudenski AS, et al. Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia. 1985;28(7):412-9. doi:10.1007/BF00280883 · PMID 3899825
  2. Wallace TM, Levy JC, Matthews DR. Use and abuse of HOMA modeling. Diabetes Care. 2004;27(6):1487-95. doi:10.2337/diacare.27.6.1487 · PMID 15161807

Formula and cut-offs checked against these sources on 8 Nov 2026. Educational tool for clinicians; it does not replace clinical judgement.

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