π§ͺ QUICKI Calculator
Insulin sensitivity from fasting labs.
For informational purposes only, not medical advice. Consult a healthcare professional.
QUICKI, the Quantitative Insulin Sensitivity Check Index, distills fasting insulin and glucose into one number for insulin sensitivity. Lower means more resistant: the pancreas must push out more insulin to hold the same glucose. Values around 0.38 are typical of insulin-sensitive adults, under 0.33 suggests resistance, and under 0.30 is commonly seen in type 2 diabetes. It correlates well with the laborious clamp studies researchers use as truth. This calculator computes it from fasting labs for education and discussion with your clinician.
How to Use This Calculator
Enter fasting insulin in uU/mL and fasting glucose in mg/dL from the same morning blood draw. The calculator returns the QUICKI index.
Use a true fasting sample: 8 to 12 hours without food, water only. Non-fasting values invalidate the index.
Enter insulin in micro-units per mL and glucose in mg/dL. If glucose is in mmol/L, multiply by 18 first.
Read the index. Around 0.38 is typical; under 0.33 suggests insulin resistance.
How the Math Works
QUICKI equals 1 divided by the sum of log base 10 of fasting insulin and log base 10 of fasting glucose. With insulin 10 and glucose 90, the logs are 1.000 and 1.954, summing to 2.954, and the reciprocal is 0.339. The log transform linearizes the hyperbolic relationship between insulin and glucose, which is why the index tracks clamp-measured sensitivity better than simple ratios like HOMA. Bands used in the literature: above 0.36 normal, 0.33 to 0.36 borderline, under 0.33 insulin resistant, under 0.30 typical of diabetes. It reflects hepatic insulin sensitivity mainly.
Worked Example
Fasting insulin 10 with glucose 90 gives a QUICKI of 0.338, which the calculator places in the Borderline band. The same glucose with insulin of 20 would drop the index to about 0.31: identical sugar, double the insulin effort, visibly worse sensitivity. That contrast is the whole point of the index: it sees the effort, not just the result.
Reading Your Result
Above 0.36 with normal glucose is reassuring. The 0.33 to 0.36 band is the nudge toward lifestyle review: activity, weight, and sleep all move insulin sensitivity. Under 0.33 suggests meaningful resistance and deserves a clinician conversation, especially with belly fat, family history, or abnormal lipids. Under 0.30 overlaps the diabetic range and needs proper diabetes evaluation. One fasting pair is a snapshot; repeat before labeling yourself.
| QUICKI | Band | Meaning |
|---|---|---|
| Above 0.36 | Normal | Typical sensitivity |
| 0.33-0.36 | Borderline | Review lifestyle |
| Under 0.33 | Resistant | Discuss with clinician |
| Under 0.30 | Low | Diabetes range, evaluate |
Limitations
QUICKI needs true fasting steady-state labs; illness, steroids, or a non-fasting sample invalidate it. Insulin assays vary between labs, so compare values only within the same lab. It estimates hepatic sensitivity and correlates with, but does not equal, whole-body clamp results. It screens and tracks; diabetes is diagnosed by glucose criteria, not by QUICKI.
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For informational purposes only, not medical advice. Consult a healthcare professional.
Frequently Asked Questions
What is QUICKI?
The Quantitative Insulin Sensitivity Check Index: 1 divided by the sum of log-transformed fasting insulin and glucose. Developed by Katz and colleagues, it is a simple fasting surrogate for insulin sensitivity that correlates well with gold-standard clamp studies. Lower values mean more insulin resistance.
What is a normal QUICKI value?
Around 0.38 in insulin-sensitive adults. Above 0.36 is generally considered normal, 0.33 to 0.36 borderline, under 0.33 suggests insulin resistance, and under 0.30 is typical of type 2 diabetes. Labs and populations shift these slightly.
How is QUICKI different from HOMA-IR?
Both use fasting insulin and glucose, but HOMA-IR multiplies them (higher means more resistant) while QUICKI log-transforms and inverts (lower means more resistant). QUICKI correlates slightly better with clamp studies in many comparisons. They tell the same story in different dialects.
Do I need to fast for QUICKI?
Yes, 8 to 12 hours, water only. The math assumes basal steady-state conditions. A non-fasting sample breaks the model completely and the number becomes meaningless. Morning draws after an overnight fast are standard.
Can exercise change my QUICKI?
Yes. Regular activity, especially with resistance training, improves insulin sensitivity and the index follows over weeks to months. Weight loss, better sleep, and less refined carbohydrate do the same. It is a useful tracker for lifestyle interventions.
Why use logs in the formula?
Because insulin and glucose relate hyperbolically: doubling insulin does not double anything linear. The log transform straightens the relationship so the index tracks true sensitivity across the range. It is the mathematical reason QUICKI outperforms simple ratios.
Is QUICKI used to diagnose diabetes?
No. Diabetes is diagnosed by fasting glucose, HbA1c, or oral glucose tolerance criteria. QUICKI describes sensitivity, which can be abnormal long before glucose criteria are met. That early-warning property is its real value.
Can medications affect QUICKI?
Yes. Steroids, some antipsychotics, and thiazides worsen insulin sensitivity; metformin and thiazolidinediones improve it. Note current medicines when interpreting, and never adjust them based on the index alone.
How often should I repeat it?
If tracking an intervention, every 3 to 6 months with consistent lab conditions. Single values fluctuate with sleep, stress, and recent diet. Trends across identical conditions are what matter.
Does QUICKI work for type 1 diabetes?
Poorly. With little endogenous insulin, fasting insulin reflects injected doses and timing rather than sensitivity. The index was validated in non-diabetic and type 2 populations. Type 1 management uses glucose data, not QUICKI.