HOMA-IR Calculator
Insulin resistance from your fasting glucose and fasting insulin. One of the most important numbers most people have never heard of.
Your lab values
Both values must be from a fasting blood sample. Insulin is often not on standard panels — you may need to request it.
Medications that may affect your result
Metformin reduces insulin resistance and will lower your HOMA-IR score. If you are on metformin, your unmedicated HOMA-IR would likely be higher than shown.
Corticosteroids (prednisone, dexamethasone) raise blood glucose and insulin resistance, which can elevate HOMA-IR independent of your baseline metabolic state.
Some antipsychotics (olanzapine, clozapine) are associated with increased insulin resistance and metabolic syndrome risk.
Insulin therapy invalidates HOMA-IR entirely. The calculation assumes endogenous insulin only.
If you are taking any of these medications, discuss your results with your healthcare provider for proper context.
About this tool
Formula
HOMA-IR = (Fasting Insulin [μIU/mL] × Fasting Glucose [mg/dL]) / 405. If glucose is entered in mmol/L, it is converted to mg/dL (×18.018) before calculation.
Classification
Optimal: below 1.0. Healthy range: 1.0–1.9. Borderline insulin resistance: 2.0–2.9. Significant insulin resistance: 3.0 and above. These thresholds reflect optimal metabolic health targets, which are stricter than many standard lab reference ranges.
Limitations
Reference ranges established largely on non-Hispanic White populations. South Asian individuals may demonstrate insulin resistance at lower thresholds. Requires a true fasting state (8–12 hours). Not valid during insulin therapy. Day-to-day variation of 20–30% is normal — a single measurement is directional, not definitive.
Sources
Matthews DR et al., Homeostasis model assessment, Diabetologia, 1985. Ascaso JF et al. and Gayoso-Diz P et al., updated clinical thresholds.
Educational tool only. Not for diagnostic purposes. Consult a healthcare provider for medical decisions.