By Zencalcy Editorial TeamLast reviewed About us
HOMA-IR is a simple index of insulin resistance built from fasting insulin and fasting glucose. It approximates how hard the body has to work to keep glucose in range: higher insulin relative to glucose suggests more resistance. This calculator accepts glucose in mg/dL or mmol/L and returns the index with the full arithmetic.
Estimate insulin resistance from fasting insulin and glucose.
HOMA-IR = fasting insulin(µU/mL) × fasting glucose(mg/dL) ÷ 405
The 405 divisor comes from the original HOMA model and assumes glucose is expressed in mg/dL. If your glucose is in mmol/L, the calculator converts it before applying the equation. HOMA-IR is a research and screening index, not a diagnosis.
| Symbol | Meaning |
|---|---|
| insulin | Fasting insulin in µU/mL. |
| glucose | Fasting glucose in mg/dL. |
| HOMA-IR | Homeostatic model assessment of insulin resistance. |
HOMA-IR = 10 × 100 ÷ 405 = 1000 ÷ 405 = 2.47. With insulin 15 µU/mL and glucose 5.5 mmol/L, the glucose first converts to 99.1 mg/dL, giving 15 × 99.1 ÷ 405 = 3.67.
In a person with normal insulin sensitivity, a small amount of insulin is enough to keep fasting glucose steady. When tissues respond poorly to insulin, the pancreas compensates by releasing more, so glucose may remain normal while insulin climbs. HOMA-IR captures that trade-off by multiplying the two values. The index is inexpensive because it uses tests that are already common, but it inherits their limitations. Insulin assays are not standardised across laboratories, and fasting glucose has its own pre-analytical variation. A single result is therefore best read as a broad indicator. Trends over months, measured under the same conditions, are more informative than small differences between two readings.
Continue with the Blood Sugar Converter, Estimated Average Glucose Calculator, or the A1c Calculator — or browse more diabetes tools and all health calculators.
Yes. The index assumes fasting insulin and fasting glucose, usually after at least eight hours without eating. A non-fasting sample does not fit the model and can give a misleading result.
These tools convert or screen laboratory values using published formulas. They do not diagnose diabetes, insulin resistance or ketoacidosis, and they do not calculate an insulin dose. Laboratory methods vary; confirm results with the reporting lab and a clinician. DKA symptoms need urgent medical care.
Reference material used to build and check this calculator:
Last reviewed: September 2026. See how we build and check every tool on the about page.
Content updated: September 2026