The normal range of hemoglobin A1c for a diabetes-free person is 5.6 percent or less, according to MedlinePlus. Values from 5.7 to 6.4 percent imply prediabetes, while 6.5 percent and above indicate that the person is diabetic. The normal range may differ between laboratories.
Hemoglobin A1c is a blood test that shows a 3-month average blood glucose level, as MedlinePlus explains. Doctors administer this test on diabetic patients, usually at 3- or 6-month intervals, to determine the ability of the patients to manage their blood glucose. The test can take place in the laboratory, at the care provider's office or at home using a special test kit.