Estimated average glucose (eAG) is a glucose concentration level calculated from a patient's Hb A1C result. In 2008, the ADA recommended the use of this new term and that this calculation be performed and reported routinely with the measured A1C result.
The formula for conversion of Hb A1C to glucose in mg/dL is: eAG = 28.7 x A1C – 46.7
The eAG is essentially a health tool to help clinicians set glucose level targets in patients, especially useful in cases where the patient is not entirely compliant and where patients do not check their blood glucose frequently enough to keep proper track through self monitoring. The ADA introduced the term to help translate the A1C results into numbers that are closer to every day readings on glucose meters.