Calculate Your Estimated A1C
Based on Nathan DM et al. Translating the A1C assay into estimated average glucose values. NEJM 2008.
Glucose unit:
Enter your average blood glucose over the past 2–3 months. You can find this in your meter's history, CGM app, or log. If you don't have an average, use the individual readings tab instead.
Add your recent individual readings and we'll calculate the average and your estimated A1C. Enter at least 3 readings for a meaningful estimate.
Average: —
Estimated A1C
—
%
—
<5.7%
5.7–6.4%
6.5–7.9%
8%+
—
—
A1C to Average Glucose Reference Table
| A1C | Avg glucose (mg/dL) | Avg glucose (mmol/L) | Zone |
|---|
Formula: This tool uses the Nathan et al. equation: eAG (mg/dL) = 28.7 × A1C − 46.7 (or equivalently: A1C = (eAG + 46.7) / 28.7). Published in Nathan DM et al., Diabetes Care 2008;31(8):1473–1478. This is the same formula used by the ADA. This estimate is not a laboratory test — it should not be used for diagnosis. Always confirm A1C with a certified laboratory test ordered by your healthcare provider.