Also named: Hemoglobin A1C; glycosylated hemoglobin; HbA1c.

This test gives average blood glucose over the last two-three months. Your A1C should be checked every three months if your blood glucose is not meeting target ranges. Once you are stable, every six months is recommended.

This test measures the amount of blood glucose attached to red blood cells. If your blood has higher than normal amounts of “sugar” in it over time, the red blood cells can get “sticky” from too much contact with the glucose. Red blood cells have a lifespan of three months, and so as you improve your blood glucose control, your A1C will improve over time.

Normal A1C is six percent. Your target is seven percent or less.



A1c and Long-Term Complications



You can estimate your average glucose over the three months from your A1C number with this calculation:

A1C level x (multiplied by) 33.3 – 86 = average blood glucose level for the past 90 days.

The following chart is an easy way to understand what your A1C means in average glucose levels:

A1c (percent) Estimated Average Glucose
6 126
6.5 140
7 154
7.5 169
8 183
8.5 197
9 212
9.5 226
10 240
10.5 255
11 269



Reviewed by Clara Schneider MS, RD, RN, CDE, LDN - 05/13