QUICKI Calculator
Medically reviewed by Dr. Chhaya Makhija, MD, DipABLM — September 2026
Calculate the Quantitative Insulin Sensitivity Check Index (QUICKI) from fasting glucose and fasting insulin. QUICKI is a validated alternative to HOMA-IR with better linear discrimination in the normal sensitivity range. Educational reference only.
📉 QUICKI Calculator
QUICKI Result
(for comparison)
component
component
Most people arrive at QUICKI having already met HOMA-IR, and reasonably wonder why a second index exists for the same two blood tests. The answer is that the two numbers are built for different jobs.
Both start from fasting glucose and fasting insulin. HOMA-IR multiplies them, producing a scale that climbs steeply — useful when resistance is severe, but crowding everyone in the healthy range into a narrow strip near the bottom where small laboratory differences look like meaningful change. QUICKI takes the logarithm of each value instead and inverts the result, which spreads out the normal range at the cost of compressing the extremes.
The practical consequence is that QUICKI runs in the opposite direction to HOMA-IR. A higher QUICKI means better insulin sensitivity; a lower one means more resistance. Values almost always fall between about 0.30 and 0.45, and a shift of 0.02 that looks trivial is not.
Below the calculator you will find the reference ranges, a worked example showing the arithmetic, both indices computed side by side from the same blood results, and the unit conversion that catches out anyone whose lab reports insulin in pmol/L.
QUICKI Reference Ranges
| QUICKI Value | Interpretation |
|---|---|
| > 0.45 | High insulin sensitivity |
| 0.339 – 0.45 | Normal sensitivity range |
| 0.30 – 0.339 | Reduced sensitivity — borderline |
| < 0.30 | Significant insulin resistance |
The 0.339 threshold was identified by Katz et al. (2000) using euglycemic clamp validation. Obese individuals may have values near 0.30; type 2 diabetes patients typically fall below 0.30.
QUICKI Formula
Unlike HOMA-IR, QUICKI uses a logarithmic transformation that linearizes the glucose-insulin relationship, providing better discrimination in the normal and near-normal sensitivity range. Higher QUICKI = better insulin sensitivity (opposite direction to HOMA-IR).
How QUICKI differs from HOMA-IR
QUICKI and HOMA-IR start from the same two fasting numbers — glucose and insulin — but they treat them differently. HOMA-IR multiplies the pair, so its values climb steeply as resistance worsens. QUICKI instead takes the logarithm of each value and inverts the result, which compresses the scale into a narrow band, usually between about 0.30 and 0.45. The practical effect is that QUICKI moves in the opposite direction to HOMA-IR: a lower QUICKI means more insulin resistance, while a higher number reflects better sensitivity.
Because the log transformation softens the extreme readings that can distort HOMA-IR, many researchers find QUICKI tracks more tightly with gold-standard clamp studies, especially in people with obesity or diabetes. If you've seen both scores quoted, they're describing the same physiology from two mathematical angles rather than disagreeing.
Why QUICKI can be more stable across populations
Fasting insulin is a noisy measurement — it varies between lab assays and can swing with a single off day. By taking logarithms, QUICKI dampens that noise, so a modest blip in insulin shifts the score far less than it would shift HOMA-IR. That stability is part of why QUICKI is often chosen for comparing groups in research and for following one person over time.
Reading your QUICKI score in context
As a rough guide, values around 0.45 and above suggest good insulin sensitivity, the mid-0.30s point toward emerging resistance, and figures near 0.30 or below are seen in established insulin resistance and type 2 diabetes. Exact cut-offs differ by study and population, and the index shares HOMA-IR's limits: it needs a proper fast, it reflects one moment in time, and it is a screening estimate, not a diagnosis. Read it together with the rest of your metabolic picture.
Worked Example
The logarithms make QUICKI look harder than it is. Taking a fasting insulin of 8 µIU/mL and a fasting glucose of 90 mg/dL:
A QUICKI of 0.350 sits in the normal sensitivity band, comfortably above the 0.339 threshold Katz identified but not in the high-sensitivity range. The same pair gives a HOMA-IR of 1.78 — also normal. Both indices agree, as they usually do; what differs is how they behave as things worsen.
QUICKI and HOMA-IR, Side by Side
Running the same fasting pairs through both formulas shows exactly why the two indices feel so different to read:
| Fasting insulin | Fasting glucose | QUICKI | HOMA-IR | Interpretation |
|---|---|---|---|---|
| 3 µIU/mL | 80 mg/dL | 0.420 | 0.59 | High sensitivity |
| 5 µIU/mL | 85 mg/dL | 0.380 | 1.05 | Normal |
| 8 µIU/mL | 90 mg/dL | 0.350 | 1.78 | Normal |
| 15 µIU/mL | 100 mg/dL | 0.315 | 3.70 | Borderline / reduced |
| 25 µIU/mL | 110 mg/dL | 0.291 | 6.79 | Insulin resistant |
| 30 µIU/mL | 126 mg/dL | 0.280 | 9.33 | Marked resistance |
HOMA-IR calculated as (glucose mg/dL × insulin µIU/mL) ÷ 405.
Look at the two middle columns across the whole table. From the most sensitive row to the most resistant, QUICKI moves from 0.420 to 0.280 — a change of a third. Over the same span, HOMA-IR moves from 0.59 to 9.33 — roughly sixteenfold.
That is the entire trade-off. HOMA-IR's wide scale makes severe resistance unmistakable but crowds the healthy range into a narrow strip near the bottom, where small assay differences produce large-looking swings. QUICKI's compressed scale gives better resolution among people who are broadly normal, which is precisely where screening usually needs to discriminate — at the cost of making the difference between "resistant" and "very resistant" look smaller than it is.
Neither is more correct. If you are tracking your own change over time in the normal-to-borderline range, QUICKI's stability is an advantage. If you want a number that shouts when resistance is severe, HOMA-IR does that better.
If Your Lab Reports Insulin in pmol/L
The QUICKI formula requires fasting insulin in µIU/mL (equivalently mIU/L). Many labs outside the United States report pmol/L instead, and entering that figure directly produces a badly wrong result — the logarithm of a number roughly seven times too large.
Example: a reported fasting insulin of 55.6 pmol/L → 55.6 ÷ 6.945 = 8.0 µIU/mL.
Glucose has the same problem in the other direction: the formula expects mg/dL, while most of the world reports mmol/L. Multiply mmol/L by 18.0182 to convert — 5.0 mmol/L is 90 mg/dL.
A quick sanity check before trusting any QUICKI result: fasting insulin in µIU/mL is normally a single- or low-double-digit number. If you have entered something in the fifties or hundreds, you are almost certainly still in pmol/L.
Moving your QUICKI in the right direction
Because QUICKI rises as sensitivity improves, the aim is to nudge it upward — and the levers are the familiar ones: steady weight loss if you carry excess fat, regular movement (particularly after meals), resistance training to build glucose-hungry muscle, fewer refined carbohydrates, and consistent sleep. Changes show up over weeks to months, so retest under the same fasting conditions and watch the trend rather than a single reading.
Frequently Asked Questions
What is a normal QUICKI value?
A QUICKI between about 0.339 and 0.45 indicates normal insulin sensitivity. Values of 0.30–0.339 are borderline, and below 0.30 suggests significant insulin resistance. Higher QUICKI means better sensitivity — the opposite direction to HOMA-IR.
How is QUICKI calculated?
QUICKI = 1 ÷ [log₁₀(fasting insulin in µIU/mL) + log₁₀(fasting glucose in mg/dL)]. The logarithms are taken of the same fasting values used for HOMA-IR.
What is the difference between QUICKI and HOMA-IR?
Both use fasting glucose and insulin, but QUICKI applies a logarithmic transformation that discriminates better in the normal sensitivity range. A high HOMA-IR means more resistance, while a high QUICKI means more sensitivity.
My lab reports insulin in pmol/L — what do I enter?
Divide by 6.945 to convert pmol/L into the µIU/mL the formula expects — 55.6 pmol/L is 8.0 µIU/mL. Entering pmol/L directly gives a badly wrong result, because the logarithm is taken of a number about seven times too large. A quick check: fasting insulin in µIU/mL is normally a single or low double-digit figure, so anything in the fifties or hundreds is still in pmol/L.
Why does QUICKI barely change when HOMA-IR changes a lot?
Because of the logarithm. Across a span where HOMA-IR rises roughly sixteenfold — from 0.59 to 9.33 — QUICKI moves only from 0.420 to 0.280. The compression is deliberate: it gives better resolution among people in the normal range, where screening usually needs to discriminate, at the cost of making severe resistance look less dramatic. Neither index is more accurate; they emphasise different parts of the scale.
Is a higher or lower QUICKI better?
Higher is better. A higher QUICKI value reflects greater insulin sensitivity; a lower value reflects more insulin resistance.
Sources
- Katz A et al. "Quantitative insulin sensitivity check index: a simple, accurate method for assessing insulin sensitivity in humans." J Clin Endocrinol Metab. 2000;85(7):2402–2410. Link
Written by Ryan Mitchell · Last updated: September 2026