QUICKI Calculator

Q: What units does QUICKI need?

Fasting insulin in µIU/mL (identical to mIU/L) and fasting glucose in mg/dL. These are not the SI units most laboratories outside the United States report. Divide a pmol/L insulin by 6 and multiply an mmol/L glucose by 18 before using the formula.

Q: Is the logarithm in QUICKI base 10 or natural?

Base 10. The original formula uses log₁₀ of both values. Using the natural logarithm produces a number roughly 2.3 times smaller, which will not match any published threshold — a common error in reimplementations of the index.

Q: What is a normal QUICKI value?

In the original validation cohort healthy non-obese adults averaged about 0.366 to 0.382, obese subjects about 0.331 and people with type 2 diabetes about 0.304. The most commonly cited threshold for insulin resistance is below 0.357. Higher values indicate greater insulin sensitivity.

Q: Should I use QUICKI or HOMA-IR?

Either, but not both. They are computed from the same fasting insulin and glucose and are related by an exact algebraic transform, so they carry identical information. HOMA-IR has the more familiar clinical scale; QUICKI's log transform gives a roughly normal distribution better suited to statistical analysis.

Q: Can I compare my QUICKI with someone else's?

Only if both were measured in the same laboratory on the same insulin assay. Insulin immunoassays are not standardised between manufacturers and differ in their cross-reactivity with proinsulin and analogues, so the absolute value is not transferable between laboratories.

The quantitative insulin sensitivity check index, from fasting insulin in µIU/mL and fasting glucose in mg/dL — neither of which is the unit this site's own converters display.

Last updated 4 Sep 2026

QUICKI

Fasting insulin + glucose

Fasting insulin (µIU/mL)µIU/mL, not pmol/L. µIU/mL and mIU/L are the same number; divide a pmol/L insulin by 6.

Fasting glucose (mg/dL)mg/dL, not mmol/L. Multiply an mmol/L glucose by 18.

0.375QUICKIExample

Fasting insulin 5.5 µIU/mL with fasting glucose 85 mg/dL

Formula

QUICKI = 1 ÷ (log₁₀[fasting insulin in µIU/mL] + log₁₀[fasting glucose in mg/dL])

log₁₀: the base-10 logarithm, not the natural log. Using ln gives a number about 2.3 times smaller and makes every published band meaningless
µIU/mL: numerically identical to mIU/L, and NOT pmol/L. Divide a pmol/L insulin by 6 first; this site's insulin converter displays pmol/L
mg/dL: NOT mmol/L. Multiply an mmol/L glucose by 18 first; this site's glucose converter displays mmol/L
fasting: both values must come from the same genuinely fasting sample, eight hours or more; a post-prandial insulin makes the index meaningless

Worked example

Fasting insulin 5.5 µIU/mL with fasting glucose 85 mg/dL
log₁₀(5.5) = 0.7404
log₁₀(85) = 1.9294
0.7404 + 1.9294 = 2.6698
1 ÷ 2.6698 = 0.375
The same sample in SI units is 33 pmol/L insulin and 4.7 mmol/L glucose — neither of which can be put into this formula

Reported values

These are population means from a small validation cohort, not guideline thresholds. Because insulin assays differ between manufacturers, a laboratory's own data is preferable where it exists.
Group	QUICKI	Source
Healthy, non-obese adults	about 0.366 – 0.382 (mean)	Katz et al, 2000 validation cohort
Obese, non-diabetic adults	about 0.331 (mean)	Katz et al, 2000
Type 2 diabetes	about 0.304 (mean)	Katz et al, 2000
Commonly cited insulin-resistance threshold	< 0.357	Lower bound of the healthy range
Correlation with the euglycaemic clamp	r ≈ 0.61	Comparable to HOMA-IR at r ≈ 0.60

QUICKI against HOMA-IR

The two indices are built from the same fasting insulin and glucose, so neither confirms the other. Choose one and be consistent.
	QUICKI	HOMA-IR
Formula	1 ÷ log₁₀(insulin × glucose)	insulin × glucose ÷ 405
Relationship	QUICKI = 1 ÷ log₁₀(405 × HOMA-IR) — an exact transform	The same two numbers, untransformed
Direction	Higher means more insulin sensitive	Higher means more insulin resistant
Distribution	Roughly normal, from the log transform	Skewed; usually log-transformed for analysis
Best used for	Group comparison and statistical analysis	Clinical conversation, where the scale is familiar
Reporting both	Adds nothing — they contain identical information	Adds nothing — they contain identical information

Two units to get right, and one index that is really two

QUICKI is the reciprocal of the sum of two base-10 logarithms: the fasting insulin in µIU/mL and the fasting glucose in mg/dL. Both units matter and both differ from what most laboratories outside the United States print, and from what this site’s own converters display — insulin in pmol/L and glucose in mmol/L. Divide a pmol/L insulin by 6, multiply an mmol/L glucose by 18, and only then use this calculator. Feeding SI units into the formula produces a plausible-looking number that means nothing. The logarithm is base 10; using the natural log gives a result about 2.3 times smaller and detaches it from every published band.

The index was published by Katz and colleagues in 2000 and validated against the euglycaemic hyperinsulinaemic clamp, which remains the reference method for measuring insulin sensitivity. In that cohort, healthy non-obese adults averaged around 0.366 to 0.382, obese non-diabetic subjects around 0.331 and people with type 2 diabetes around 0.304, and the lower bound of the healthy range, 0.357, has since become the most commonly quoted threshold for insulin resistance. Those are population means from a small study rather than guideline cut-offs.

QUICKI and HOMA-IR are not two independent measures of the same thing. They are built from the same two numbers, and the relationship between them is exact rather than approximate: since log(insulin) + log(glucose) is log(insulin × glucose), and HOMA-IR is that product divided by 405, QUICKI is simply 1 divided by the base-10 logarithm of 405 times HOMA-IR. Each is a strictly monotonic transform of the other, so they correlate almost perfectly and neither can ever confirm the other. Reporting both adds no information at all.

Which to use follows from that. HOMA-IR has the more familiar scale, where 1.0 is the model’s normal and larger is worse, and it is what most clinicians and most papers will recognise. QUICKI’s log transform makes the distribution roughly normal, which is why it is preferred for statistical analysis and for comparing groups. The limitation both share is the insulin assay: immunoassays are not standardised between manufacturers, and they differ in how much proinsulin and which insulin analogues they detect, so a QUICKI from one laboratory is not the same quantity as a QUICKI from another. Neither index diagnoses anything; both are interpreted by a clinician alongside the rest of the picture.

Frequently asked questions

What units does QUICKI need?

Fasting insulin in µIU/mL (identical to mIU/L) and fasting glucose in mg/dL. These are not the SI units most laboratories outside the United States report. Divide a pmol/L insulin by 6 and multiply an mmol/L glucose by 18 before using the formula.

Is the logarithm in QUICKI base 10 or natural?

Base 10. The original formula uses log₁₀ of both values. Using the natural logarithm produces a number roughly 2.3 times smaller, which will not match any published threshold — a common error in reimplementations of the index.

What is a normal QUICKI value?

In the original validation cohort healthy non-obese adults averaged about 0.366 to 0.382, obese subjects about 0.331 and people with type 2 diabetes about 0.304. The most commonly cited threshold for insulin resistance is below 0.357. Higher values indicate greater insulin sensitivity.

Should I use QUICKI or HOMA-IR?

Either, but not both. They are computed from the same fasting insulin and glucose and are related by an exact algebraic transform, so they carry identical information. HOMA-IR has the more familiar clinical scale; QUICKI’s log transform gives a roughly normal distribution better suited to statistical analysis.

Can I compare my QUICKI with someone else's?

Only if both were measured in the same laboratory on the same insulin assay. Insulin immunoassays are not standardised between manufacturers and differ in their cross-reactivity with proinsulin and analogues, so the absolute value is not transferable between laboratories.

Related calculators

References

Katz A, Nambi SS, Mather K, 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.
Hrebíček J, Janout V, Malinčíková J, Horáková D, Čížek L. Detection of insulin resistance by simple quantitative insulin sensitivity check index QUICKI for epidemiological assessment and prevention. J Clin Endocrinol Metab. 2002;87(1):144–147.
Muniyappa R, Lee S, Chen H, Quon MJ. Current approaches for assessing insulin sensitivity and resistance in vivo: advantages, limitations, and appropriate usage. Am J Physiol Endocrinol Metab. 2008;294(1):E15–E26.