Last updated October 13, 2026 · Report an error
This calculator converts hemoglobin A1c to average blood sugar (and back), using the ADA-published ADAG formula: eAG (mg/dL) = 28.7 x A1C - 46.7. It is powered by the same engine as our Estimated Average Glucose Calculator — "A1c Calculator" and "eAG Calculator" are both common, distinct search terms for the identical conversion, so we list both rather than force one term. This calculator is for general reference and educational purposes only — it is not a medical diagnosis. Consult a doctor or qualified professional for actual diabetes management decisions.
How it works
Choose a direction (A1C to average blood sugar, or the reverse), then enter the known value. The tool applies the ADAG formula (or its algebraic reverse) and reports the result in both mg/dL and mmol/L.
- Enter conversion direction.
- Enter value (A1C % or eAG mg/dL, per direction above).
- Click Calculate to see your results.
Examples
A1C of 7%
Average blood sugar = 28.7 x 7 - 46.7 = 154.2 mg/dL (about 8.56 mmol/L).
Who should use it
- Understanding what an A1c lab result means in everyday glucose-meter terms.
- Patient education material relating A1c to daily glucose numbers.
Industry applications
- Diabetes education and patient communication
- Primary care reference
Advantages
- Uses the same formula published and endorsed by the American Diabetes Association (ADA).
- Works in both directions and reports both common units.
Limitations
- An estimate — individual correlation between A1c and average glucose can vary.
- Does not account for conditions that can affect A1c accuracy.
Common mistakes to avoid
- Treating average blood sugar as a single reading rather than an estimate over roughly 2-3 months.
- Mixing up mg/dL and mmol/L when comparing to a home glucose meter.
Best practices
- Compare your eAG to your meter's average reading over the same period for a sanity check.
Tips
- Discuss your A1c trend over time with your doctor, not just a single value.