A1c ↔ Average Glucose Converter
A1c and average glucose describe the same thing — your blood sugar over roughly the past 2–3 months — on two different scales. This converter runs in both directions using the ADAG study equation: enter your A1c to see your estimated average glucose (eAG), or enter your average glucose to see the equivalent A1c.
A1c → estimated average glucose
From your most recent lab report
Enter your value above to see the result.
Average glucose → A1c
From a CGM average or your meter's average reading
Enter your value above to see the result.
This result is a screening estimate, not a diagnosis. Discuss your labs with a qualified healthcare professional.
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How it works
The formula
eAG (mg/dL) = 28.7 × A1c − 46.7. Reverse: A1c = (average glucose + 46.7) ÷ 28.7. The equation comes from the ADAG study, which paired continuous glucose monitoring with A1c measurements across hundreds of participants to derive the linear relationship.
Quick reference chart
A1c 4% ≈ 68 mg/dL · 5% ≈ 97 mg/dL · 5.7% ≈ 117 mg/dL · 6% ≈ 126 mg/dL · 6.5% ≈ 140 mg/dL · 7% ≈ 154 mg/dL · 8% ≈ 183 mg/dL · 9% ≈ 212 mg/dL · 10% ≈ 240 mg/dL.
Limitations
The A1c–glucose relationship is a population average — individual variation exists (anemia, kidney disease, recent transfusion, and some genetic variants can shift A1c independently of glucose). An eAG estimate never replaces a lab-measured A1c, and neither value alone is a diagnosis.
Frequently asked questions
How do I convert A1c to average blood glucose?
Multiply your A1c by 28.7 and subtract 46.7 to get estimated average glucose in mg/dL. For example, an A1c of 7% works out to about 154 mg/dL. This converter does the math in both directions instantly.
What is eAG on my lab report?
eAG stands for estimated average glucose — your A1c re-expressed in the same mg/dL units you see on a glucose meter, derived from the ADAG study equation. Some labs report it automatically alongside A1c; ours calculates it for you either way.
My meter or CGM shows mmol/L — how do I convert?
Divide the mg/dL result by 18 to get mmol/L (e.g. 154 mg/dL ≈ 8.6 mmol/L). To go the other way, multiply mmol/L by 18 before entering it here.
Is an estimated A1c from average glucose as accurate as a lab A1c?
No. The estimate assumes your glucose average is representative of a full 2–3 month window and that your A1c behaves like the population average. A lab A1c is the reference standard — use the estimate for orientation, not for decisions.
Is this converter a diagnosis?
No. A1c and eAG values are screening information. Diagnosis of any condition requires a qualified healthcare professional evaluating lab results in the context of your history and symptoms.
Sources
- Nathan DM, et al. Translating the A1C assay into estimated average glucose values (ADAG study). Diabetes Care, 2008.
- American Diabetes Association. Standards of Care in Diabetes — Glycemic Goals and Hypoglycemia. Diabetes Care, 2025.
This calculator is for informational purposes only and is not medical advice, diagnosis, or treatment. Reference ranges are general population guidelines — always discuss your lab results with a qualified healthcare professional.