What is it:

An estimated average glucose (EAG) is the average amount of glucose in the blood over a 2 to 3 month period. It is calculated based on the amount of glycosylated hemoglobin in the blood, which indicates how glucose levels have been regulated in the lifespan of a red blood cell (about 2 to 3 months).

Although this test can be used to monitor the average amount of glucose in the blood, there is no set reference range for a normal estimated average glucose level is. However, values above 126 mg/dL, or 7.0 mmol/L are considered to be elevated.

It is important for an endocrinologist to assess a monitor EAG results and interpret them according to each individual patient’s health history and diabetes management.

What it’s for

EAG is used to monitor the average amount of glucose in the person’s blood. It gives insight into a patient’s glucose levels in the last 2 to 3 months. It may be useful for monitoring diabetes evolution and to evaluate treatment responses.

Reference ranges

An EAG is used by using the glycosylated hemoglobin, or HB1C level, in the blood. You can see the reference values below:

HBA1C (%)	Estimated Average Glucose (mg/dL)	Estimated Average Glucose (mmol/L)
6	126	7.0
6.5	140	7.8
7	154	8.6
7.5	169	9.4
8	183	10.1
8.5	197	10.9
9	212	11.8
9.5	226	12.6
10	240	13.4

Another way to calculate the estimated average glucose level is to obtain the HBA1C result as a % and multiply it by 28.7. Then subtract 46.7 to get a result. The formula for this calculation is: eAG (mg/dL) = 28.7 × A1C(%) – 46.7.

Normal levels

Normal levels of EAG generally vary from 68 to 126 mg/dL. These are calculated using glycosylated hemoglobin results. However, there is no specific cut-off point for normal values, and levels can vary depending on the method prescribed by the doctor to manage blood sugar.

Normal glucose level

To know whether your glucose level is within a normal range, select the type of glucose test you completed and enter the result below:

What results mean

Estimated average glucose levels above 126 mg/dL or 7.0 mmol/L generally show that blood glucose levels have frequently been elevated in the 2 to 3 months prior to the test. It means that a patient is at a higher risk for diabetes, or that sugar levels have been poorly managed during this time.

Results should be interpreted by an endocrinologist to determine the most appropriate treatment and plan of action.