About the QUICKI
QUICKI (Quantitative Insulin Sensitivity Check Index) is a formula that estimates whole-body insulin sensitivity from a single fasting blood draw. Published by Katz and colleagues in 2000, it was derived to correlate with the euglycemic-clamp technique, the labor-intensive research gold standard for measuring insulin sensitivity, while needing only two routine lab values: fasting insulin and fasting glucose.
How the score is calculated
The formula takes the base-10 logarithm of fasting insulin (in microU/mL) and the base-10 logarithm of fasting glucose (in mg/dL), adds them together, and inverts the sum:
- QUICKI = 1 / [log10(insulin) + log10(glucose)]
- If glucose is entered in mmol/L, it is first converted to mg/dL (multiply by 18.0182) before the logarithm is taken, since the published formula uses mg/dL.
- Because both terms are logarithms, insulin and glucose must both be greater than zero, and QUICKI itself is unitless.
Putting the result in context
Unlike a ratio, QUICKI moves in the same direction as insulin sensitivity: a higher score means more sensitive (less resistant), and a lower score means less sensitive. In the original validation cohorts, mean QUICKI was about 0.382 in normal-weight subjects, about 0.331 in obese subjects, and about 0.304 in subjects with type 2 diabetes. These are group averages from one study, not universal cutoffs, and the exact threshold used to flag insulin resistance varies with the population studied and the insulin assay used.
When to consult a professional
This calculator performs the published QUICKI arithmetic; it does not diagnose insulin resistance, prediabetes, or diabetes. Fasting insulin and glucose values, and how to interpret them, should be reviewed with a licensed healthcare provider who has your full lab panel and history.