A1C of 6.9% is an average glucose of 151 mg/dL

Estimated average glucose at A1C 6.9%

151 mg/dL

In mmol/L: 8.4 mmol/L
A1C entered: 6.9%
ADA range: the range the ADA uses to diagnose diabetes

At 6.9%, the estimated average glucose works out to 151 mg/dL (8.4 mmol/L). If your report uses IFCC units instead of a percentage, the equivalent is around 52 mmol/mol.

The ADA sets its diabetes threshold at 6.5%. A value here should be interpreted by a clinician together with a repeat test; the arithmetic on this page only translates the number into an average glucose.

Each additional tenth of a percentage point adds about 3 mg/dL to the estimated average, so 7.0% works out to roughly 154 mg/dL. That step is smaller than the 0.5-point tolerance NGSP allows on the assay, which is worth holding in mind before reading much into a one-tenth difference.

This is a single frame from a moving picture. A1C summarises a period, so one value locates you on the scale while telling you nothing about which direction you were travelling.

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.

Convert a different A1C value

A1C to estimated average glucose, 6.4% to 7.4%
A1C	eAG (mg/dL)	eAG (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
7.4%	166 mg/dL	9.2 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 average blood sugar does an A1C of 6.9% mean?

The estimate is 151 mg/dL, equivalently 8.4 mmol/L, from the published ADA conversion for an A1C of 6.9%.

Where does 6.9% fall on the ADA scale?

The ADA describes 6.9% 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.

What should I ask my clinician about 6.9%?

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.

How precise is the 151 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.

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