By Zencalcy Editorial TeamLast reviewed About us
Estimated average glucose translates an A1c percentage into the average blood glucose level it usually reflects. A1c measures the share of haemoglobin that has been glycated over roughly the previous two to three months, so the estimate is a long-run average rather than a single reading. This calculator returns eAG in both mg/dL and mmol/L.
Turn an A1c percentage into estimated average glucose.
| Enter the A1c percentage, for example 7.0. |
eAG(mg/dL) = 28.7 × A1c(%) − 46.7 eAG(mmol/L) = eAG(mg/dL) ÷ 18.0182
The equation comes from the ADAG study relationship between A1c and continuously measured average glucose. It predicts a population average, so an individual's true average can fall above or below the estimate.
| Symbol | Meaning |
|---|---|
| A1c | Glycated haemoglobin percentage. |
| eAG | Estimated average glucose in mg/dL. |
| 28.7 and 46.7 | Coefficients of the ADAG linear relationship. |
eAG = 28.7 × 7.0 − 46.7 = 200.9 − 46.7 = 154.2 mg/dL. Dividing by 18.0182 gives 8.56 mmol/L. An A1c of 6.0% gives 172.2 − 46.7 = 125.5 mg/dL, or 6.97 mmol/L.
Estimated average glucose is most useful as a bridge between a lab number and the readings people see every day. An A1c of 7 percent sounds abstract until it is expressed as an average near 154 mg/dL or 8.6 mmol/L. That said, an average hides variation. Two people can share the same eAG while one stays steady and the other swings between highs and lows. If your meter or sensor shows wide excursions, the average alone understates the work required. Use eAG to understand the overall level, then look at time in range, post-meal peaks and overnight lows to see how that level is produced. Bring both views to a clinical review rather than treating the estimated average as a grade.
Continue with the Blood Sugar Converter, A1c Calculator, or the HOMA-IR Calculator — or browse more diabetes tools and all health calculators.
It is the average blood glucose that would typically produce your A1c. It is not a lab measurement of glucose itself; it is a value derived from the A1c percentage using a population equation.
These tools convert or screen laboratory values using published formulas. They do not diagnose diabetes, insulin resistance or ketoacidosis, and they do not calculate an insulin dose. Laboratory methods vary; confirm results with the reporting lab and a clinician. DKA symptoms need urgent medical care.
Reference material used to build and check this calculator:
Last reviewed: September 2026. See how we build and check every tool on the about page.
Content updated: September 2026