Lab calculator
HOMA-IR calculator
HOMA-IR turns a fasting glucose and a fasting insulin result into one number that estimates insulin resistance. It is a research index, not a diabetes test, and there is no single cutoff that says you have insulin resistance.
Your fasting results
Both values should come from the same fasting blood draw. Nothing you enter leaves this page.
What you will see
Your HOMA-IR value and how to read it, without a made-up "normal" line.
Educational only, not medical advice. HOMA-IR cannot diagnose diabetes or prediabetes.
Source
Matthews DR et al., Diabetologia 1985 (the homeostasis model assessment and its near-approximation formula).
Validated in
Checked against clamp tests in small groups of adults in Oxford, UK: for example 12 people without diabetes and 11 with type 2 diabetes in the euglycemic clamp comparison.
Limits
An estimate built for research, with no cutoff in the original paper. Not a test for diabetes or prediabetes. The authors noted it depends on the precision of the insulin test. Not meaningful if you take insulin.
The formula
The 1985 paper gives a near approximation of its model: insulin resistance equals fasting insulin (µU/mL) times fasting glucose (mmol/L), divided by 22.5 (Matthews 1985). With glucose in mg/dL, we first divide by 18, which is the same as dividing insulin times glucose by 405. If your lab reports insulin in pmol/L, we first divide it by 6 to get µIU/mL, the conversion factor for human insulin (1 µIU/mL = 6.00 pmol/L) (Knopp 2019). Some calculators and lab sheets use an older factor of about 6.95, so your result may differ slightly from one worked out that way (Knopp 2019). The model treats normal-weight people without diabetes under age 35 as having a resistance of 1 (Matthews 1985).
In the original study, the HOMA estimate of insulin resistance tracked closely with the euglycemic clamp, the reference research method, in people with and without type 2 diabetes (Matthews 1985). In that clamp comparison, the median value was 1.21 in the people without diabetes and 2.89 in the people with diabetes (Matthews 1985). Those are averages from small study groups, not cutoffs.
Why there is no "normal" line here
The original paper does not set a cutoff for insulin resistance (Matthews 1985). The National Institute of Diabetes and Digestive and Kidney Diseases says health care professionals may not test for insulin resistance, and that the test is used mainly in research studies (NIDDK). The paper's authors also warned that a HOMA estimate from fasting insulin is unlikely to be precise: it depends on how precise the insulin test is, and on pulses of insulin release, stress and exercise (Matthews 1985). So a cut point taken from one study or lab may not fit your result, and we show your value without labelling it normal or high.
Not a diabetes test
Diabetes and prediabetes are diagnosed with an A1C, a fasting plasma glucose or an oral glucose tolerance test, not with HOMA-IR (ADA Standards 2026). Your fasting glucose on its own already tells you more for that question: see prediabetes ranges and next steps. To see your overall chance of type 2 diabetes, take the diabetes risk test. Insulin resistance often goes with a larger waist, high blood pressure and abnormal blood fats; see the metabolic syndrome criteria.
Sources
- 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.org/10.1007/BF00280883
- Knopp JL, Holder-Pearson L, Chase JG. Insulin Units and Conversion Factors: A Story of Truth, Boots, and Faster Half-Truths. J Diabetes Sci Technol. 2019;13(3):597-600. doi.org/10.1177/1932296818805074
- National Institute of Diabetes and Digestive and Kidney Diseases (NIH). Insulin Resistance & Prediabetes. www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/prediabetes-insulin-resistance
- American Diabetes Association Professional Practice Committee. 2. Diagnosis and Classification of Diabetes: Standards of Care in Diabetes 2026. Diabetes Care. 2026;49(Suppl 1):S27-S49. doi.org/10.2337/dc26-S002
Written and maintained by the uncovermyrisk.com editorial team. We do not have a medical reviewer; every claim links to its primary source above. Last reviewed: 2026-10-31. Spotted an error? See About.