Comparison of blood glucose, hba1c, and fructosamine by tom bartol, rn-c, mn, fnp, cde: to convert the a1c to average blood glucose, consider the high end of the normal range (e.g. if normal is 4-6%, then 6%) is equal to 120 mg/dl. for each change in 1% of a1c, there is a corresponding increase or decrease of approximately 30 mg/dl average.in addition, fructosamine levels decrease more quickly.
