HOMA-IR — Insulin Resistance Calculator

HOMA-IR (Homeostatic Model Assessment for Insulin Resistance) is a simple marker of insulin resistance based on fasting plasma glucose and fasting insulin. It was introduced by Matthews et al. in 1985 and is now in worldwide clinical use.

The classic formula is HOMA-IR = (fasting insulin in µU/mL × fasting glucose in mg/dL) / 405. In SI units it is HOMA-IR = (insulin µU/mL × glucose mmol/L) / 22.5.

Values below 1.5 are considered normal. 1.5 to 1.99 suggests mild insulin resistance, 2.0 to 2.89 indicates insulin resistance and ≥ 2.9 is severe. Exact cut-offs vary by lab and population.

HOMA-IR is helpful when there is suspicion of insulin resistance — for example in PCOS, non-alcoholic fatty liver disease, obesity or prediabetes. It supports an early estimate of diabetes risk.

Acute illness, stress, glucocorticoids, recent meals, pregnancy and some medications can shift insulin or glucose. The test requires an 8–12 hour fast.

An elevated value is a warning sign, not a diagnosis. Weight loss, regular physical activity and a carbohydrate-aware diet measurably improve insulin sensitivity. Discuss next steps such as HbA1c or an oral glucose tolerance test with your physician.