A1C conversion chart
| A1C % | mmol/mol | eAG mg/dL | eAG mmol/L |
|---|---|---|---|
| 5.0% | 31 | 97 | 5.4 |
| 5.5% | 37 | 111 | 6.2 |
| 6.0% | 42 | 126 | 7.0 |
| 6.5% | 48 | 140 | 7.7 |
| 7.0% | 53 | 154 | 8.5 |
| 7.5% | 58 | 169 | 9.3 |
| 8.0% | 64 | 183 | 10.1 |
| 8.5% | 69 | 197 | 10.9 |
| 9.0% | 75 | 212 | 11.7 |
| 9.5% | 80 | 226 | 12.5 |
| 10.0% | 86 | 240 | 13.3 |
| 10.5% | 91 | 255 | 14.1 |
| 11.0% | 97 | 269 | 14.9 |
| 11.5% | 102 | 283 | 15.7 |
| 12.0% | 108 | 298 | 16.5 |
What A1C tells you
A1C, also called HbA1c, measures how much sugar is attached to your red blood cells. Because red blood cells live for about three months, it reflects your average blood sugar over roughly the last two to three months. It is measured in a lab or clinic, usually every three to six months.
The estimated average glucose (eAG) turns that percentage into the same units your meter shows. The formula comes from the A1C-Derived Average Glucose (ADAG) study, which compared A1C with thousands of glucose readings in over 500 people: eAG (mg/dL) = 28.7 × A1C − 46.7.
Why your log still matters
Two people with the same A1C can have very different days: one steady, the other swinging between highs and lows. A1C shows the average; your log shows the swings, and when they happen. That is why your doctor looks at both.
My own HbA1c has stayed below 6% for twenty years with type 1 diabetes, most of the time around 5.2–5.5%. The daily paper log is a big part of how I got there. That is my result with my own treatment, not a target for you: your A1C goal comes from your doctor.
Make your blood sugar logPrint a log that fits how you test, in mmol/L or mg/dL.Questions
What is estimated average glucose (eAG)?
It is the average blood sugar that matches a given A1C, calculated with a formula from the ADAG study published in Diabetes Care in 2008: eAG (mg/dL) = 28.7 × A1C − 46.7.
Why does my meter average differ from my eAG?
Your meter only sees the moments you test, often before meals when levels are lower. A1C reflects the whole day and night over about three months. The eAG is also an estimate: in the study, real averages for the same A1C varied from person to person.
What is a good A1C?
For many adults with diabetes the ADA suggests below 7% (53 mmol/mol); NICE suggests 6.5% (48 mmol/mol) or lower for adults with type 1 diabetes. Your own goal depends on your situation and is set with your doctor.
What are mmol/mol?
The IFCC unit for HbA1c, used in the UK and much of Europe. 48 mmol/mol equals 6.5%. Convert with (A1C% − 2.15) × 10.929.
Can I use this to diagnose diabetes?
No. Diagnosis needs lab tests done by a health professional. This calculator only translates an A1C result into an average glucose.
Sources
- Nathan DM, et al. Translating the A1C assay into estimated average glucose values. Diabetes Care 2008;31(8):1473–1478
- American Diabetes Association. eAG/A1C Conversion Calculator
- American Diabetes Association. 6. Glycemic Goals, Hypoglycemia, and Hyperglycemic Crises: Standards of Care in Diabetes—2026. Diabetes Care 2026;49(Suppl 1)
- NICE guideline NG17. Type 1 diabetes in adults: diagnosis and management