A1C of 5.4% is an average glucose of 108 mg/dL
Estimated average glucose at A1C 5.4%
108 mg/dL
- In mmol/L
- 6 mmol/L
- A1C entered
- 5.4%
- ADA range
- below the range the ADA defines as prediabetes
At 5.4%, the estimated average glucose works out to 108 mg/dL (6 mmol/L). If your report uses IFCC units instead of a percentage, the equivalent is around 36 mmol/mol.
Below the ADA prediabetes range. Since A1C depends on the lifespan of red blood cells, anything that shortens that lifespan pulls the number down independently of your glucose.
A1C 5.4% draws a lot of searches, usually from someone checking whether it is "close" to 5.7%. Arithmetically it is three tenths away. Practically, the assay tolerance is wider than that gap, so a 5.4% and a 5.6% from the same person weeks apart may not represent any real change at all.
For comparison, 5.5% comes out at approximately 111 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.
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.
The estimated average is a summary of a summary: your A1C summarises months, and the conversion summarises the relationship between A1C and glucose across a whole study population.
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.
| A1C | eAG (mg/dL) | eAG (mmol/L) |
|---|---|---|
| 4.9% | 94 mg/dL | 5.2 mmol/L |
| 5.0% | 97 mg/dL | 5.4 mmol/L |
| 5.1% | 100 mg/dL | 5.5 mmol/L |
| 5.2% | 103 mg/dL | 5.7 mmol/L |
| 5.3% | 105 mg/dL | 5.8 mmol/L |
| 5.4% | 108 mg/dL | 6 mmol/L |
| 5.5% | 111 mg/dL | 6.2 mmol/L |
| 5.6% | 114 mg/dL | 6.3 mmol/L |
| 5.7% | 117 mg/dL | 6.5 mmol/L |
| 5.8% | 120 mg/dL | 6.7 mmol/L |
| 5.9% | 123 mg/dL | 6.8 mmol/L |
- Estimated average glucose (ADAG / Nathan) — eAG (mg/dL) = 28.7 x A1C - 46.7. Verified 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 5.4% in average blood sugar?
Is 5.4% inside the ADA prediabetes range?
How precise is the 108 mg/dL figure?
What should I ask my clinician about 5.4%?
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