What is the QUICKI formula?

QUICKI = 1 / [log10(fasting insulin, µU/mL) + log10(fasting glucose, mg/dL)]. Both values must come from the same fasting blood draw, typically after an 8–12 hour fast.

How is QUICKI different from HOMA-IR?

Both are calculated from the same two fasting labs, but QUICKI applies a log transform to insulin and glucose before combining them, while HOMA-IR multiplies the raw values. The two indices move in opposite directions: QUICKI falls as insulin resistance rises, while HOMA-IR rises as insulin resistance rises.

What QUICKI value indicates insulin resistance?

Cutoffs vary across validation studies, but a QUICKI at or above 0.38 is generally considered normal insulin sensitivity, 0.34–0.379 borderline or reduced, and below 0.34 is consistent with insulin resistance. Treat these as reference bands, not a fixed diagnostic line.

Can QUICKI diagnose insulin resistance or diabetes on its own?

No. QUICKI is a research and screening index derived from two fasting labs. It is not a standalone diagnostic and should be interpreted alongside the full clinical picture, including other metabolic findings and a clinician's judgment.

What can throw off a QUICKI result?

A non-fasted blood draw, hemolyzed or delayed-processing insulin samples, and inter-assay variability between insulin immunoassays can all skew the insulin term and therefore the QUICKI result.

QUICKI Calculator — Insulin Sensitivity Check Index

QUICKI	Interpretation
≥ 0.38	Normal insulin sensitivity
0.34 – 0.379	Borderline / reduced insulin sensitivity
< 0.34	Consistent with insulin resistance

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Walk-through

How to Use This Calculator

3 steps

1

Enter fasting insulin and glucose

Type the fasting insulin (µU/mL) and fasting glucose from the same blood draw, typically taken after an 8–12 hour fast. Glucose defaults to mg/dL — switch the unit dropdown to mmol/L if that is how your lab reports it, and the calculator converts automatically before computing QUICKI.

2

Read the QUICKI result and sensitivity tier

The result card shows your QUICKI value, an insulin-sensitivity tier (normal, borderline, or consistent with resistance), and the HOMA-IR computed from the same two labs for reference. Remember that QUICKI moves opposite to HOMA-IR: lower QUICKI means more insulin resistant.

3

Open the Interpretation and Compare tabs

The Interpretation tab shows the full reference-band table and the factors that can skew a result. The Compare to HOMA-IR tab puts both indices side by side and explains why they exist together and why they move in opposite directions.

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Reference

Formula & Methodology

2 formulas

QUICKI

QUICKI = 1 / [log10(fasting insulin, µU/mL) + log10(fasting glucose, mg/dL)]

Katz et al.'s 2000 log-transformed insulin-sensitivity index. Both inputs must be strictly greater than zero (the log of zero or a negative number is undefined). Glucose entered in mmol/L is converted to mg/dL first by multiplying by 18.0182.

HOMA-IR (shown for reference)

HOMA-IR = (fasting glucose, mg/dL × fasting insulin, µU/mL) / 405

Matthews et al.'s 1985 homeostasis model, computed from the same two fasting labs and displayed alongside QUICKI on the Compare tab. HOMA-IR rises as insulin resistance rises — the opposite direction from QUICKI.

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High YMYL

Trust, Methodology & Sources

Reviewed by Calculover Editorial Review · Updated 2026-07-23 · 3 sources

Editorial accountability

Author: Calculover Clinical Team - Clinical content team

Owner: Calculover Editorial - Editorial oversight

Reviewer: Calculover Editorial Review - Clinical-source review

Last reviewed: 2026-07-23

Last verified: 2026-07-23

Data effective: 2026-07-23

Methodology

The calculator implements the QUICKI formula from Katz A, et al., J Clin Endocrinol Metab. 2000;85(7):2402-2410: QUICKI = 1 / [log10(fasting insulin, µU/mL) + log10(fasting glucose, mg/dL)]. Glucose entered in mmol/L is converted to mg/dL (× 18.0182) before the formula is applied. Both inputs must be strictly greater than zero. For reference, the calculator also computes HOMA-IR (Matthews DR, et al., Diabetologia. 1985;28(7):412-419) from the same two values: HOMA-IR = (glucose mg/dL × insulin µU/mL) / 405. Interpretation bands (≥0.38 normal, 0.34–0.379 borderline, <0.34 consistent with resistance) were compiled from multiple published validation studies and are presented as a general reference range, not a single authoritative cutoff, since published thresholds vary by population and assay.

Assumption: Fasting insulin and fasting glucose are entered from the same blood draw, typically taken after an 8–12 hour fast.

Assumption: Fasting insulin is entered in µU/mL (equivalent to µIU/mL); fasting glucose defaults to mg/dL with an optional mmol/L conversion.

Assumption: A single QUICKI value is treated as a research/screening data point, not a diagnosis of insulin resistance or diabetes.

Limitations & guidance

Interpretation cutoffs for insulin resistance vary across published validation studies and populations; this calculator presents a general reference range rather than one universally agreed threshold.

Fasting insulin measurement is highly dependent on the specific immunoassay used, so the same blood sample can give different results at different labs.

QUICKI does not capture non-fasting-state factors, medication effects, or other components of metabolic syndrome; it should be interpreted alongside the full clinical picture, not in isolation.

Professional guidance: This calculator is for research, screening, and educational reference only and is not medical advice, diagnosis, or treatment. QUICKI does not diagnose insulin resistance or diabetes on its own — results must be interpreted by a qualified clinician alongside the full clinical picture.

Primary sources

Quantitative insulin sensitivity check index: a simple, accurate method for assessing insulin sensitivity in humans - Katz A, Nambi SS, Mather K, et al. J Clin Endocrinol Metab. 2000;85(7):2402-2410

Detection of insulin resistance by simple quantitative insulin sensitivity check index QUICKI for epidemiological assessment and prevention - Hrebicek J, Janout V, Malincikova J, et al. J Clin Endocrinol Metab. 2002;87(1):144-147

Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man - Matthews DR, Hosker JP, Rudenski AS, et al. Diabetologia. 1985;28(7):412-419

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Glossary

Key Terms Explained

5 terms

QUICKI The Quantitative Insulin Sensitivity Check Index — a log-transformed insulin-sensitivity score computed from fasting glucose and fasting insulin. Higher values mean more insulin sensitive; lower values mean more insulin resistant.

Insulin resistance A reduced biological response to insulin, meaning the body needs more insulin than usual to move glucose out of the bloodstream. It is a hallmark of prediabetes, type 2 diabetes, and metabolic syndrome.

HOMA-IR The Homeostatic Model Assessment for Insulin Resistance — a companion index computed from the same two fasting labs as QUICKI, but without the log transform. HOMA-IR rises as resistance rises, the opposite direction from QUICKI.

Fasting insulin The concentration of insulin in the blood after an 8–12 hour fast, measured in µU/mL (equivalent to µIU/mL). Highly dependent on the specific immunoassay used, which is one reason cutoffs vary across labs and studies.

Euglycemic clamp The hyperinsulinemic-euglycemic clamp technique — the labor-intensive research reference standard for measuring insulin sensitivity directly. QUICKI and HOMA-IR were both validated against clamp-derived insulin sensitivity in their original publications.

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Scenarios

Real-World Examples

3 worked examples

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Healthy fasting labs

Lean, metabolically healthy adult

Fasting insulin 5 µU/mL Fasting glucose 85 mg/dL

QUICKI = 1 / (log10(5) + log10(85)) ≈ 0.38 — right at the normal insulin-sensitivity band (≥ 0.38). The same labs give a HOMA-IR of about 1.05, also consistent with normal sensitivity. Both indices agree here because the fasting glucose and insulin are both comfortably in a healthy range.

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Borderline case

Mildly elevated fasting insulin

Fasting insulin 10 µU/mL Fasting glucose 100 mg/dL

QUICKI = 1 / (log10(10) + log10(100)) = 1/3 ≈ 0.333 — below the 0.34 cutoff, consistent with insulin resistance. HOMA-IR from the same values is about 2.47, also in a commonly-flagged range. A fasting glucose at the top of normal plus a fasting insulin roughly double the lean example is enough to move both indices into the resistant zone.

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Marked insulin resistance

High fasting insulin with borderline glucose

Fasting insulin 25 µU/mL Fasting glucose 110 mg/dL

QUICKI = 1 / (log10(25) + log10(110)) ≈ 0.291 — well below 0.34, clearly consistent with insulin resistance. HOMA-IR from the same values is about 6.79. Because QUICKI compresses the insulin term with a logarithm, a 5× jump in fasting insulin (5 → 25 µU/mL) only moves QUICKI from 0.38 to 0.291, while HOMA-IR moves from about 1.05 to 6.79 — the two indices scale very differently even though they use the same inputs.

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Deep Dive

Understanding QUICKI and Insulin Sensitivity

3 chapters · 4 min read

QUICKI turns two routine fasting labs — glucose and insulin — into a single number that estimates how sensitive your body is to insulin. Developed by Katz and colleagues in 2000 as a simpler, log-transformed alternative to the labor-intensive euglycemic clamp, QUICKI is used mainly in research and screening contexts rather than as a standalone clinical diagnostic.

How QUICKI works

QUICKI takes the base-10 logarithm of fasting insulin (µU/mL) and fasting glucose (mg/dL), adds them together, and inverts the sum: QUICKI = 1 / [log10(insulin) + log10(glucose)]. The log transform compresses large swings in fasting insulin, which is why QUICKI tends to move in a narrower, more linear-feeling range (roughly 0.30–0.45) than its cousin HOMA-IR.

Because QUICKI is built from a reciprocal, it moves in the opposite direction from insulin resistance: a higher QUICKI means more insulin sensitive, and a lower QUICKI means more insulin resistant. This is the single most common point of confusion for people used to reading HOMA-IR, where higher numbers mean more resistance.

QUICKI vs. HOMA-IR

QUICKI and HOMA-IR are computed from the exact same two fasting labs, but combine them differently: HOMA-IR multiplies glucose and insulin directly and divides by a constant (405), while QUICKI takes the log of each value first. In Katz et al.'s original validation against the hyperinsulinemic-euglycemic clamp — the gold-standard, labor-intensive research measure of insulin sensitivity — QUICKI correlated somewhat more consistently with the clamp result than HOMA-IR did, particularly across a wider range of body weights.

In practice, the two indices are complementary rather than competing: many research and screening protocols report both, since they can occasionally disagree at the margins even though they are highly correlated overall.

Limits and what to check next

QUICKI is a research and screening index, not a standalone diagnostic. Interpretation cutoffs vary meaningfully across published validation studies and populations (commonly cited insulin-resistance thresholds range from about 0.30 to 0.36), so treat any single QUICKI value as a data point rather than a verdict. The insulin measurement itself is also highly assay-dependent — different labs and different immunoassay kits can give meaningfully different fasting insulin numbers for the same blood sample, which shifts QUICKI along with it.

A single fasting insulin/glucose pair does not capture the whole metabolic picture. Clinicians typically interpret QUICKI (or HOMA-IR) alongside waist circumference, triglycerides, HDL cholesterol, blood pressure, and A1C rather than in isolation, and a formal diagnosis of insulin resistance, prediabetes, or diabetes requires clinical evaluation beyond this calculator.

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Questions

Frequently Asked Questions

5 questions

What does the QUICKI Calculator actually compute?+

It computes the Quantitative Insulin Sensitivity Check Index from a fasting insulin and fasting glucose value: QUICKI = 1 / [log10(fasting insulin, µU/mL) + log10(fasting glucose, mg/dL)]. A higher QUICKI means more insulin sensitive; a lower QUICKI means more insulin resistant — the opposite direction from HOMA-IR, which the calculator also computes for reference on the Compare tab.

How accurate is this calculator?+

The formula matches Katz et al.'s original 2000 publication in the Journal of Clinical Endocrinology & Metabolism exactly. The interpretation bands, however, are a general reference range compiled from multiple validation studies — actual cutoffs for insulin resistance vary by population, assay, and study, so results should be interpreted alongside other clinical findings rather than as a fixed pass/fail threshold.

What units does the QUICKI Calculator expect?+

Fasting insulin is entered in µU/mL (equivalent to µIU/mL, the standard unit for this formula). Fasting glucose defaults to mg/dL, with an optional mmol/L toggle — the calculator converts mmol/L to mg/dL internally (× 18.0182) before computing QUICKI or HOMA-IR.

Can I share my results?+

Yes. The calculator encodes your inputs into the URL hash as you type, and the Share button copies a link that restores those same values when opened — useful for sharing a specific scenario with a colleague or saving it for later.

Where does the data come from?+

QUICKI comes from 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. The reference HOMA-IR value comes from Matthews DR, et al., Diabetologia. 1985;28(7):412-419.

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QUICKI Calculator

Fasting Labs

QUICKI Result

What Your QUICKI Means

QUICKI vs. HOMA-IR

How to Use This Calculator

Enter fasting insulin and glucose

Read the QUICKI result and sensitivity tier

Open the Interpretation and Compare tabs

Formula & Methodology

Trust, Methodology & Sources

Key Terms Explained

Real-World Examples

Healthy fasting labs

Borderline case

Marked insulin resistance

Understanding QUICKI and Insulin Sensitivity

How QUICKI works

QUICKI vs. HOMA-IR

Limits and what to check next

Frequently Asked Questions

Get a branded PDF of your results

QUICKI Calculator

Fasting Labs

QUICKI Result

What Your QUICKI Means

QUICKI vs. HOMA-IR

How to Use This Calculator

Enter fasting insulin and glucose

Read the QUICKI result and sensitivity tier

Open the Interpretation and Compare tabs

Formula & Methodology

Trust, Methodology & Sources

Key Terms Explained

Real-World Examples

Understanding QUICKI and Insulin Sensitivity

How QUICKI works

QUICKI vs. HOMA-IR

Limits and what to check next

Frequently Asked Questions

Get a branded PDF of your results

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