HOMA-IR Calculator

HOMA-IR (Homeostatic Model Assessment for Insulin Resistance) is a mathematical model published by Matthews et al. in 1985 that estimates insulin resistance from two routine fasting blood values: fasting insulin and fasting glucose. When cells respond poorly to insulin, the pancreas releases more of it to keep glucose steady, so the product of the two values rises. HOMA-IR captures that relationship in a single number. It is an estimate, not a diagnosis — insulin resistance assessment needs clinical context.

HOMA-IR = (fasting insulin in µU/mL × fasting glucose in mmol/L) ÷ 22.5. If your glucose is reported in mg/dL, use HOMA-IR = (fasting insulin in µU/mL × fasting glucose in mg/dL) ÷ 405, or first convert glucose to mmol/L by dividing by 18. Both inputs must come from the same fasting blood draw, taken after at least 8 hours without food.

Commonly cited ranges — cutoffs vary by population and assay — are: below 1.0 optimal insulin sensitivity; 1.0 to 2.5 the normal range; above 2.5 suggesting insulin resistance. A cutoff of 2.5 or higher is widely used (NHANES uses ≥2.5), and values between 2.0 and 3.0 are commonly used in clinical and research settings. Some populations, for example several Asian cohorts, use lower cutoffs around 1.4–2.5. Treat any single number as a screening signal, not a verdict — trends over time in the same person are usually more informative.

A HOMA-IR above 2.5 is the commonly cited threshold suggesting insulin resistance — meaning the body may need more insulin than usual to keep fasting glucose steady. It does not diagnose insulin resistance, prediabetes, or diabetes on its own. Clinicians interpret it alongside fasting glucose, HbA1c, lipids, blood pressure, weight history, and medications before drawing conclusions.

QUICKI (Quantitative Insulin Sensitivity Check Index) was proposed by Katz et al. in 2000 as a log-transformed companion to HOMA-IR. It is calculated as QUICKI = 1 ÷ (log10(fasting insulin in µU/mL) + log10(fasting glucose in mg/dL)). Because it measures insulin sensitivity rather than resistance, higher QUICKI values are better — the opposite direction from HOMA-IR.

Commonly cited QUICKI ranges are: 0.357 and above suggesting normal insulin sensitivity; 0.339 to 0.356 borderline; below 0.339 suggesting insulin resistance. These thresholds come from validation studies against glucose-clamp measurements and vary across populations, so use them as orientation, not as a diagnosis.

They are two views of the same fasting numbers. HOMA-IR is more widely cited and its 2.5 threshold is familiar in clinical practice; QUICKI's log transform makes it more linear across the range and it correlates slightly better with clamp-measured sensitivity in validation studies. This calculator shows both so you can compare — agreement between them strengthens the signal, and the FAQ below explains what disagreement means.

It happens near the cutoffs. For example, fasting insulin 10 µU/mL with glucose 5.0 mmol/L (90 mg/dL) gives HOMA-IR 2.22 — inside the normal range — but QUICKI 0.338, just under the 0.339 threshold that suggests insulin resistance. The two indices use different math and different published cutoffs, so borderline values can land on opposite sides. When they disagree, neither overrules the other — it is a sign to look at the full clinical picture rather than one number.

Divide mg/dL by 18 to get mmol/L; multiply mmol/L by 18 to go back. For example, 90 mg/dL ÷ 18 = 5.0 mmol/L. This calculator converts automatically — just pick the unit printed on your lab report.

Divide pmol/L by 6.945 to get µU/mL (equivalently, 1 µU/mL = 6.945 pmol/L). For example, 69.45 pmol/L ÷ 6.945 = 10 µU/mL. Select pmol/L in the insulin unit dropdown and the calculator handles the conversion.

HOMA-β (beta-cell function) comes from the same Matthews et al. 1985 paper as HOMA-IR and estimates how hard the pancreatic beta cells are working: HOMA-β = (20 × fasting insulin in µU/mL) ÷ (fasting glucose in mmol/L − 3.5), expressed as a percentage of normal. Values around 100% suggest typical beta-cell function for the glucose level; it is undefined when fasting glucose is 3.5 mmol/L or lower. Like HOMA-IR, it is an estimate that needs clinical context.

No. HOMA-IR is a screening estimate, not a diagnostic test. It is unreliable in people with diagnosed diabetes, people using insulin or glucose-lowering medication, during acute illness or stress, and in some groups such as lean or elderly individuals. A high value suggests further evaluation; a normal value does not rule out metabolic problems. This tool is educational — not medical advice — and any concerning result should be discussed with a clinician.