HOMA-IR Calculator

Methodology

HOMA1 (Matthews et al., 1985)

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

The original HOMA approximation. Cut-offs for 'insulin resistance' vary widely between populations and laboratories, so no single threshold is applied here.

Who it is for

Adults without insulin treatment, fasting sample.

Version

1.0.0

How this calculator works

Where the formula comes from

• Matthews and colleagues (1985) used a computer-solved model of the glucose–insulin feedback loop to estimate insulin resistance and beta-cell deficiency from fasting glucose and insulin (homeostasis model assessment).^[1]
• HOMA insulin resistance correlated with the euglycaemic clamp (Rs 0.88), but precision was low (coefficients of variation 31% for insulin resistance and 32% for beta-cell deficit).^[1]

The inputs

• The HOMA1 approximations are insulin (µU/mL) × glucose (mmol/L) ÷ 22.5 for insulin resistance and 20 × insulin ÷ (glucose − 3.5) for beta-cell function.^[2]

Versions and alternatives

• An updated computer model (HOMA2) is available; the 1985 approximation formulae remain more widely used.^[3][2]

Where accuracy falls (published evidence)

• HOMA estimates differed with the insulin assay used; standardised assays traceable to a reference method are needed to compare results.^[4]
• Published HOMA-IR cut-offs for insulin resistance vary widely, and its distribution differs by age, sex and ethnicity.^[5]

What guidelines say

• HOMA is suited to cohort and epidemiological studies; measuring beta-cell function in isolation is described as inappropriate use.^[2]

Sources

1. Matthews DR, Hosker JP, Rudenski AS, Naylor BA, Treacher DF, Turner RC. Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia. 1985;28(7):412–419. doi:10.1007/BF00280883
2. Wallace TM, Levy JC, Matthews DR. Use and abuse of HOMA modeling. Diabetes Care. 2004;27(6):1487–1495. doi:10.2337/diacare.27.6.1487
3. Levy JC, Matthews DR, Hermans MP. Correct homeostasis model assessment (HOMA) evaluation uses the computer program. Diabetes Care. 1998;21(12):2191–2192. doi:10.2337/diacare.21.12.2191
4. Manley SE, Luzio SD, Stratton IM, Wallace TM, Clark PM. Preanalytical, analytical, and computational factors affect homeostasis model assessment estimates. Diabetes Care. 2008;31(9):1877–1883. doi:10.2337/dc08-0097
5. Tahapary DL, Pratisthita LB, Fitri NA, et al. Challenges in the diagnosis of insulin resistance: focusing on the role of HOMA-IR and tryglyceride/glucose index. Diabetes Metab Syndr. 2022;16(8):102581. doi:10.1016/j.dsx.2022.102581

Compiled from the published sources above. Every statement was agreed independently by three AI research tools (Claude, ChatGPT, DeepSeek) and its source verified in PubMed or Crossref by the Hakeemly editorial team. Not reviewed by a doctor unless stated. Agreed on 2026-10-12

Worked example: how to calculate HOMA-IR

An illustration with sample values, worked out with the same method the tool above uses.

Limitations

• Insulin assays differ between laboratories.
• Not valid in people treated with insulin.
• A research and clinical-context index, not a diagnosis.

References

1. Matthews DR, Hosker JP, Rudenski AS, Naylor BA, Treacher DF, Turner RC. Homeostasis model assessment: insulin resistance and β-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia. 1985;28(7):412–419. doi:10.1007/BF00280883