A1c to average glucose (eAG) calculator
Convert your HbA1c to an estimated average glucose (eAG) — the same units your glucose meter uses — or go the other way. Type in either box and the other updates instantly, using the standard ADAG formula.
Your privacy: this calculator runs entirely in your browser — nothing you type is sent anywhere. It's the same on-device principle Quanome is built on.
Educational reference only — not medical advice. eAG is an average estimate, not a diagnosis; interpret your A1c with a clinician.
## A1c, eAG, and what the numbers mean
| HbA1c | eAG (mg/dL) | eAG (mmol/L) | Category |
| --- | --- | --- | --- |
| 5.0% | 97 | 5.4 | Normal |
| 5.7% | 117 | 6.5 | Prediabetes threshold |
| 6.0% | 126 | 7.0 | Prediabetes |
| 6.5% | 140 | 7.8 | Diabetes threshold |
| 7.0% | 154 | 8.6 | Common treatment target |
| 8.0% | 183 | 10.2 | Above target |
| 9.0% | 212 | 11.7 | Well above target |
Categories are general reference points, not personal targets — the right A1c goal is individual and set with a clinician. See [what your HbA1c means](/blog/what-your-hba1c-means/) for the fuller picture.
## The formula
The **ADAG** study (2008) linked A1c to average glucose measured by continuous monitoring:
- **eAG (mg/dL) = 28.7 × A1c − 46.7**
- **eAG (mmol/L) = 1.59 × A1c − 2.59**
To go from a glucose value back to A1c, the tool rearranges the same equation. The estimate reflects an average over roughly **2–3 months** — the lifespan of the red blood cells that A1c is measured on.
## The rest of the picture
- **A single glucose reading** is a snapshot; see [what your fasting glucose means](/blog/what-your-fasting-glucose-means/).
- **Different units?** Our [mmol/L ↔ mg/dL converter](/tools/mmol-mg-dl-converter/) switches any glucose or HbA1c result between systems.
- A1c can read higher or lower than the true average in some conditions (anemia, recent blood loss, certain hemoglobin variants) — one reason eAG and a meter average sometimes disagree.
## Track your A1c and glucose over time — privately
The value in these numbers is the **trend**. [Quanome](/) pulls your labs, Apple Health, and even your DNA into one private timeline on your device — parsed locally, never uploaded — with an AI coach that reads your results in whichever units you use.
Track your A1c and glucose over time, privately
Quanome unifies your labs, Apple Health, and DNA into one private, on-device timeline — in your units, with an AI coach. Free on the App Store and Google Play.
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