Estimated Average Glucose Calculator
HbA1c reflects average blood glucose over the previous two to three months but is reported as a percentage, which can be hard to relate to the numbers on a glucose meter. The estimated average glucose (eAG) equation from the A1c-Derived Average Glucose study converts A1c into the same units as daily readings: eAG in mg/dL equals 28.7 times A1c minus 46.7, and dividing by 18 gives mmol/L. This calculator returns both. eAG is a population estimate that may differ from an individual's true average. This tool is educational, not a diagnosis.
eAG formula (ADAG)
eAG (mg/dL) = 28.7 * A1c - 46.7
eAG (mmol/L) = eAG (mg/dL) / 18
A1c entered in percent
Derived from the A1c-Derived Average Glucose study
The linear relationship comes from the ADAG study, which paired continuous glucose monitoring with A1c across many participants. The factor 18 converts glucose from mg/dL to mmol/L.
A1c to eAG reference points
- A1c 6 percent: about 126 mg/dL (7.0 mmol/L).
- A1c 7 percent: about 154 mg/dL (8.6 mmol/L).
- A1c 8 percent: about 183 mg/dL (10.2 mmol/L).
- A1c 9 percent: about 212 mg/dL (11.8 mmol/L).
- A1c 10 percent: about 240 mg/dL (13.4 mmol/L).
Estimated average glucose: frequently asked questions
How is estimated average glucose calculated from A1c?
The estimated average glucose (eAG) equation from the A1c-Derived Average Glucose (ADAG) study is: eAG in mg/dL equals 28.7 times A1c (in percent) minus 46.7. Dividing the mg/dL result by 18 gives the value in mmol/L.
What is HbA1c?
HbA1c (glycated hemoglobin) reflects average blood glucose over roughly the prior 2 to 3 months. It is reported as a percentage. The eAG equation translates that percentage into an average glucose value in the same units used for daily meter readings.
What A1c corresponds to common glucose levels?
An A1c of 6 percent corresponds to about 126 mg/dL, 7 percent to about 154 mg/dL, 8 percent to about 183 mg/dL and 9 percent to about 212 mg/dL, using the ADAG equation.
Why might eAG differ from my meter average?
eAG is a population-derived estimate. Individual red blood cell turnover, certain anemias and hemoglobin variants can make a person's true average glucose differ from the eAG. Discuss discrepancies with your clinician.
Is this a diagnosis?
No. This is an educational conversion between A1c and average glucose. Diabetes diagnosis and management rely on a clinician and standardized laboratory testing.
Official sources
- Centers for Disease Control and Prevention: All about your A1c.
- National Institute of Diabetes and Digestive and Kidney Diseases: The A1c test and diabetes.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.