A1C of 11% is an average glucose of 269 mg/dL

Estimated average glucose at A1C 11%

269 mg/dL

In mmol/L: 14.9 mmol/L
A1C entered: 11.0%
ADA range: the range the ADA uses to diagnose diabetes

Putting 11.0% through the ADA equation gives an estimated average glucose of 269 mg/dL — the same figure expressed as 14.9 mmol/L. Laboratories reporting in IFCC units would print that A1C as roughly 97 mmol/mol.

At this level the ADA diagnostic criteria apply. The most useful thing this page offers is the translation into an average glucose, which is often easier to hold onto than a percentage — and a reason to bring the printed report to an appointment rather than a screenshot.

For comparison, 11.1% comes out at approximately 272 mg/dL, about 3 mg/dL higher. Differences of a tenth sit under the roughly 0.5-point measurement tolerance, so neighbouring values are often indistinguishable in practice.

IFCC numbers look alarming to anyone used to percentages, because the scale is entirely different: a perfectly ordinary A1C reads as a two-digit figure in mmol/mol.

The regression tells you what this A1C corresponds to on average across people. It cannot tell you where in that spread you personally sit, and no amount of arithmetic will extract that.

An average hides shape. Two people with the same A1C can have very different days — one steady, one swinging widely — and A1C does not distinguish between them at all.

The look-back is weighted rather than even: the most recent weeks contribute more to the figure than the earliest ones, which is why an A1C moves before a full three months have passed.

Convert a different A1C value

A1C to estimated average glucose, 10.5% to 11.5%
A1C	eAG (mg/dL)	eAG (mmol/L)
10.5%	255 mg/dL	14.2 mmol/L
10.6%	258 mg/dL	14.3 mmol/L
10.7%	260 mg/dL	14.4 mmol/L
10.8%	263 mg/dL	14.6 mmol/L
10.9%	266 mg/dL	14.8 mmol/L
11.0%	269 mg/dL	14.9 mmol/L
11.1%	272 mg/dL	15.1 mmol/L
11.2%	275 mg/dL	15.3 mmol/L
11.3%	278 mg/dL	15.4 mmol/L
11.4%	280 mg/dL	15.5 mmol/L
11.5%	283 mg/dL	15.7 mmol/L

Computed with eAG (mg/dL) = 28.7 x A1C - 46.7 (Nathan 2008). mmol/L is derived from mg/dL using the glucose factor 18.0182.

Estimated average glucose (ADAG / Nathan) — eAG (mg/dL) = 28.7 x A1C - 46.7. Verified 2026-07-30 against Nathan et al., Diabetes Care 2008 (ADAG study) (A population regression: in the ADAG study, individuals at the same A1C had meaningfully different mean glucose. The A1C assay itself carries about +/- 0.5 percentage points under NGSP certification.)

Official sources

Nathan DM et al., Translating the A1C Assay Into Estimated Average Glucose Values, Diabetes Care 2008 — The ADAG study that produced the eAG equation used on this page.
American Diabetes Association — Standards of Care in Diabetes — Where the A1C ranges quoted here are defined.
NGSP — A1C assay standardisation and certification criteria — Why two lab results half a point apart can mean nothing changed.

Frequently asked questions

How much average glucose is an A1C of 11.0%?

An estimated average glucose near 269 mg/dL, or 14.9 mmol/L. This applies the ADA-published conversion to an A1C of 11.0%, and describes roughly the last three months.

Is 11.0% inside the ADA prediabetes range?

The ADA describes 11.0% as the range the ADA uses to diagnose diabetes. That is a definition of a numeric range rather than a diagnosis: the ADA asks clinicians to confirm results with a repeat test and to read them alongside your history.

How precise is the 269 mg/dL figure?

The conversion is exact arithmetic, but it is a population average: in the ADAG study, individuals at the same A1C had meaningfully different mean glucose. The assay itself also carries about half a percentage point of tolerance.

What should I ask my clinician about 11.0%?

Useful questions are what this figure is expected to do next, when it will be re-measured, and whether anything in your history affects how it should be read.

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