About this calculator
This converter translates HbA1c into estimated average glucose (eAG) using the ADA ADAG relationship. It shows both mg/dL and mmol/L so the result can be compared with common glucose-meter units.
eAG is an estimate of longer-term average glucose. It is not the same as a current fingerstick or CGM reading and can be misleading when A1C is affected by pregnancy, anemia, kidney disease, transfusion, hemoglobin variants, or recent major glucose changes.
Uses the American Diabetes Association ADAG relationship: estimated average glucose in mg/dL = 28.7 × A1C − 46.7. mmol/L is calculated by dividing mg/dL by 18.
Activated — ADA ADAG formula
HbA1c and estimated average glucose can be misleading with anemia, hemoglobin variants, pregnancy, recent transfusion, blood loss, kidney disease, liver disease, or altered red-cell turnover.
Formula and method
eAG mg/dL = 28.7 × HbA1c − 46.7. eAG mmol/L = eAG mg/dL ÷ 18.
Limitations and when not to rely on this result
- HbA1c and estimated average glucose can be misleading with anemia, hemoglobin variants, pregnancy, recent transfusion, blood loss, kidney disease, liver disease, or altered red-cell turnover.
- Use glucose monitoring and clinician advice when HbA1c does not match symptoms or meter readings.
- This converter does not diagnose diabetes or decide medication changes.
Frequently asked questions
What is eAG? +
Estimated average glucose is an A1C-derived estimate reported in the same units used by many glucose meters.
What formula does this use? +
It uses the ADA ADAG formula: eAG mg/dL = 28.7 × A1C − 46.7.
Is eAG the same as my meter average? +
Not necessarily. Meter and CGM averages depend on when and how often glucose is checked, while eAG comes from A1C.
When can A1C be misleading? +
Pregnancy, anemia, kidney disease, recent transfusion, hemoglobin variants, and recent treatment changes can make A1C less representative.
Can I change medication based on eAG? +
No. Use eAG for discussion with your clinician, not self-directed treatment changes.