A1C of 6.8% is an average glucose of 148 mg/dL

Estimated average glucose at A1C 6.8%

148 mg/dL

In mmol/L: 8.2 mmol/L
A1C entered: 6.8%
ADA range: the range the ADA uses to diagnose diabetes

Putting 6.8% through the ADA equation gives an estimated average glucose of 148 mg/dL — the same figure expressed as 8.2 mmol/L. Laboratories reporting in IFCC units would print that A1C as roughly 51 mmol/mol.

At or above 6.5%, this is in the range the ADA uses diagnostically — typically on two separate tests, or one test alongside unambiguous symptoms. The useful next step is an appointment with the actual report in hand.

To put the scale in context: 6.9% estimates out at around 151 mg/dL, some 3 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.

The precision of the reported figure invites more confidence than it deserves. A result printed to one decimal place still carries the method tolerance around it, so treat the last digit as approximate.

Writing the value and its date somewhere you will find it again is worth more than reading another page about it, because the comparison is the part that carries information.

Moving country, or moving between health systems, can change the units on your reports without anything changing in your blood. Worth checking before comparing an old result to a new one.

The conversion comes from a population regression. In the ADAG study, individuals sharing an A1C had mean glucose values spread meaningfully around the fitted line, so your own average may sit above or below this estimate.

Convert a different A1C value

A1C to estimated average glucose, 6.3% to 7.3%
A1C	eAG (mg/dL)	eAG (mmol/L)
6.3%	134 mg/dL	7.4 mmol/L
6.4%	137 mg/dL	7.6 mmol/L
6.5%	140 mg/dL	7.8 mmol/L
6.6%	143 mg/dL	7.9 mmol/L
6.7%	146 mg/dL	8.1 mmol/L
6.8%	148 mg/dL	8.2 mmol/L
6.9%	151 mg/dL	8.4 mmol/L
7.0%	154 mg/dL	8.5 mmol/L
7.1%	157 mg/dL	8.7 mmol/L
7.2%	160 mg/dL	8.9 mmol/L
7.3%	163 mg/dL	9 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

What is an A1C of 6.8% in average blood sugar?

Roughly 148 mg/dL (8.2 mmol/L). The figure comes from the ADAG regression, eAG = 28.7 x A1C - 46.7, applied to an A1C of 6.8%.

How does the ADA describe an A1C of 6.8%?

The ADA describes 6.8% 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.

Can something other than glucose produce an A1C of 6.8%?

Yes. Anaemia, recent blood loss, transfusion, pregnancy, chronic kidney disease and some haemoglobin variants all shift A1C independently of glucose, in either direction.

Does an A1C of 6.8% tell me about my glucose swings?

No. It is an average, and averages hide shape. Two people with this same A1C can have very different daily ranges; continuous monitoring is what shows that pattern.

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