How Does an A1C Compare to Glucose Level?

For people with diabetes, the home blood glucose test they perform regularly with a handheld glucometer tells them how much glucose is in their bloodstream at a given moment in time. The A1C, on the other hand, is a test done in a laboratory that evaluates the average amount of the extra glucose in your blood over the past 60 to 90 days.

Identification

• The home glucometer measures the milligrams of glucose in a deciliter of your blood (mg/dl). The lab reports the A1C result as the percentage of hemoglobin molecules that have glucose bound to them (%).

Considerations

• In order to control blood glucose and avoid complications of diabetes, people need to track how they are doing on a particular day (blood glucose) as well as how they are doing overall (A1C).

History

• While the A1C does a great job of measuring diabetes control over time, many people with diabetes had trouble grasping the fact that a blood glucose of 200 mg/dl was equivalent to an A1C of 7.78 percent.

Expert Insight

• The American Diabetes Association (ADA) now recommends the term "estimated average glucose" (eAG). Like the A1C, the eAG reflects average glucose levels over the past two to three months, but it's reported in the same mg/dl as the readings from the glucometer.

Tip

• The American Diabetis Association has an online calculator that can be used to translate A1C to an eAG and vice versa.