A1C of 9% is an average glucose of 212 mg/dL

Estimated average glucose at A1C 9%

212 mg/dL

In mmol/L: 11.8 mmol/L
A1C entered: 9.0%
ADA range: the range the ADA uses to diagnose diabetes

At 9.0%, the estimated average glucose works out to 212 mg/dL (11.8 mmol/L). If your report uses IFCC units instead of a percentage, the equivalent is around 75 mmol/mol.

The ADA treats 6.5% and above as diagnostic, with confirmation. Nothing on this page can tell you what happens next, because that depends on your other results, your history and a conversation this site is not part of.

To put the scale in context: 9.1% estimates out at around 214 mg/dL, some 2 mg/dL above this figure. Because assay tolerance spans roughly 0.5 percentage points, a shift of one tenth tells you very little on its own.

Certification sets how far a method may sit from the reference standard, which is not the same as a confidence interval for one person on one day. The practical upshot is the same: small differences deserve a shrug.

One question that reliably produces a useful answer: is there anything about me that makes this particular test harder to interpret? Your clinician can answer that; a calculator cannot.

If your report shows a larger number in mmol/mol rather than a percentage, that is IFCC units, used across the UK, Australia and much of Europe. The two describe the same measurement.

The equation was fitted across 507 people. It describes that group well; it describes any one member of it only approximately, which is precisely why the word "estimated" is in the name.

Convert a different A1C value

A1C to estimated average glucose, 8.5% to 9.5%
A1C	eAG (mg/dL)	eAG (mmol/L)
8.5%	197 mg/dL	10.9 mmol/L
8.6%	200 mg/dL	11.1 mmol/L
8.7%	203 mg/dL	11.3 mmol/L
8.8%	206 mg/dL	11.4 mmol/L
8.9%	209 mg/dL	11.6 mmol/L
9.0%	212 mg/dL	11.8 mmol/L
9.1%	214 mg/dL	11.9 mmol/L
9.2%	217 mg/dL	12 mmol/L
9.3%	220 mg/dL	12.2 mmol/L
9.4%	223 mg/dL	12.4 mmol/L
9.5%	226 mg/dL	12.5 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

If my A1C is 9.0%, what is my average glucose?

About 212 mg/dL, which is 11.8 mmol/L. That comes from multiplying 9.0 by 28.7 and subtracting 46.7 — the equation the ADAG study produced and the ADA publishes.

Does 9.0% count as prediabetes or diabetes?

The ADA describes 9.0% 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.

Is 9.0% a target?

This page converts a number rather than recommending one. Glycemic targets are individualised by a clinician according to your diagnosis, your other results and your risk of hypoglycaemia.

Would a different lab report the same 9.0%?

Not necessarily. Analytical methods vary between laboratories, and a point-of-care fingerstick can read differently from a venous draw, so comparisons are cleanest within one lab.

Get a quarterly nudge to re-check your numbers

Four emails a year: a reminder to re-take your numbers, and what changed in the guidance behind these tools. No spam, unsubscribe any time.

Double opt-in: you will get one confirmation email and nothing else until you click it.