Last reviewed 2026-06-20 · Source: U.S. NIDDK (NIH).
The A1C test is a blood test that shows your average blood glucose over the past 3 months. It doesn't replace daily checks — it gives the longer-term picture.
Source: NIDDK — The A1C Test & Diabetes
| Normal | below 5.7% |
| Prediabetes | 5.7% to 6.4% |
| Diabetes | 6.5% or above |
Source: NIDDK — The A1C Test & Diabetes
Studies show many people with diabetes can lower their risk of complications by keeping A1C below 7%.
But this is not one-size-fits-all: "People will have different A1C targets, depending on their diabetes history and their general health. You should discuss your A1C target with your health care professional." A less strict goal (for example, 7–8%) may be right for some people — such as those with limited life expectancy, a history of severe low blood sugar, or advanced complications.
Source: NIDDK — The A1C Test & Diabetes
Experts recommend people with diabetes have an A1C test at least twice a year. Your A1C can also be shown as an estimated average glucose (eAG) in the same mg/dL units as your meter — though eAG won't match any single moment's reading.
Source: NIDDK — The A1C Test & Diabetes