HOMA-IR Insulin Resistance Calculator
The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) estimates insulin resistance from a single pair of fasting blood values. It multiplies fasting insulin by fasting glucose and divides by a constant: 405 when glucose is measured in mg/dL, or 22.5 when glucose is in mmol/L. Higher values indicate greater resistance. HOMA-IR is widely used in research and screening for metabolic conditions. Enter fasting insulin in microunits per mL and fasting glucose in your chosen unit. This is an educational estimate, not a diagnosis, and should be interpreted by a clinician.
HOMA-IR formula
mg/dL: HOMA-IR = (insulin * glucose) / 405
mmol/L: HOMA-IR = (insulin * glucose) / 22.5
Insulin in uU/mL; both forms give the same index
Both glucose and insulin must be fasting
The two constants reflect the unit of glucose only: 405 equals 22.5 times 18, where 18 converts mmol/L to mg/dL. The index is unitless.
Interpreting HOMA-IR
- Values near 1.0 are typical of insulin-sensitive individuals.
- Higher values indicate greater insulin resistance.
- There is no universal cutoff; thresholds vary by population and insulin assay.
- Both samples must be drawn fasting and simultaneously.
- Always interpret against your laboratory's own reference range.
HOMA-IR: frequently asked questions
How is HOMA-IR calculated?
The original HOMA-IR formula multiplies fasting insulin (microunits per mL) by fasting glucose and divides by a constant: 405 when glucose is in mg/dL, or 22.5 when glucose is in mmol/L. Both forms give the same index value.
What is a normal HOMA-IR?
There is no single universal cutoff because reference ranges vary by population and assay. Values around 1.0 are typical for insulin-sensitive individuals, and higher values suggest greater insulin resistance. Interpret against your lab's reference range and clinical context.
Do glucose and insulin need to be fasting?
Yes. HOMA-IR requires simultaneous fasting glucose and fasting insulin, drawn after an overnight fast. Non-fasting values invalidate the index.
What units does the calculator support?
Fasting insulin is entered in microunits per mL (uU/mL or mIU/L). You can choose fasting glucose in mg/dL (constant 405) or mmol/L (constant 22.5); the calculator applies the matching constant.
Is HOMA-IR a diagnosis?
No. It is a research and screening estimate of insulin resistance, not a diagnostic test. It should be interpreted by a clinician alongside other findings. This tool is for education only.
Official sources
- National Institute of Diabetes and Digestive and Kidney Diseases: Insulin resistance and prediabetes.
- National Library of Medicine (NCBI): HOMA model literature.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.