A good A1C level is below 5.7%, which is considered normal for adults without diabetes. The A1C test measures your average blood sugar over the past three months by looking at how much sugar has attached to hemoglobin, a protein in your red blood cells. Everyone has some sugar-coated hemoglobin, but higher blood sugar means a larger percentage of your red blood cells carry that coating.
Normal, Prediabetes, and Diabetes Ranges
The three A1C categories are straightforward. Below 5.7% is normal. Between 5.7% and 6.4% falls into the prediabetes range, meaning your blood sugar is elevated but not high enough for a diabetes diagnosis. At 6.5% or above, the result meets the diagnostic threshold for type 2 diabetes.
These numbers aren’t arbitrary cutoffs. They reflect the point at which risk of complications, particularly damage to blood vessels, nerves, and organs, begins to climb meaningfully. A reading in the prediabetes zone doesn’t mean diabetes is inevitable, but it does signal that your body is having a harder time processing sugar than it should.
What Your A1C Means in Everyday Blood Sugar
A1C percentages can feel abstract. A more intuitive way to think about it is through estimated average glucose (eAG), which translates your A1C into the kind of blood sugar number you’d see on a glucose meter. The conversion formula is simple: multiply your A1C by 28.7, then subtract 46.7. That gives you your average blood sugar in mg/dL.
Here’s what that looks like in practice:
- A1C of 6%: average blood sugar around 126 mg/dL
- A1C of 7%: average blood sugar around 154 mg/dL
- A1C of 8%: average blood sugar around 183 mg/dL
- A1C of 9%: average blood sugar around 212 mg/dL
- A1C of 10%: average blood sugar around 240 mg/dL
For context, a fasting blood sugar below 100 mg/dL is considered normal. If your A1C is 7%, your blood sugar is averaging well above that threshold throughout the day and night, even during sleep and between meals.
A1C Targets if You Have Diabetes
If you’ve already been diagnosed with diabetes, “good” shifts from below 5.7% to a more realistic management target. For most adults with type 2 diabetes, the goal is to keep A1C below 7%. That level is associated with significantly lower rates of nerve damage, kidney disease, and vision problems compared to higher readings.
That said, targets are personalized. Older adults or people with other serious health conditions may have a somewhat higher target, because pushing blood sugar too low carries its own risks, including dangerous drops (hypoglycemia) that can cause dizziness, confusion, or falls. Younger adults with a recent diagnosis and no complications typically aim for the tightest control possible.
For children and adolescents with type 1 diabetes, the American Diabetes Association recommends an individualized target, with below 7% appropriate for many kids. Achieving this consistently can be challenging given growth spurts, hormonal changes, and the unpredictability of daily life at younger ages.
A1C Goals During Pregnancy
Pregnancy calls for tighter blood sugar control than usual. Most guidelines recommend an A1C of 6.5% or lower before becoming pregnant and below 6% once pregnancy is underway. These stricter targets exist because elevated blood sugar during pregnancy raises the risk of several complications: the baby growing unusually large (over about 10 pounds), which increases injury risk during delivery, as well as preeclampsia, a dangerous condition involving high blood pressure. The likelihood of needing a C-section also rises when blood sugar stays elevated.
What Can Throw Off Your Results
The A1C test works by measuring sugar attached to hemoglobin, so anything that changes your hemoglobin or red blood cells can skew the result. Anemia, recent blood loss, blood transfusions, and certain inherited hemoglobin variants can all make your A1C read artificially high or low. Kidney disease and iron deficiency can also distort the number.
If you have any of these conditions and your A1C doesn’t match what your day-to-day glucose readings suggest, a different type of blood sugar test may give a more accurate picture. This is especially relevant for people of African, Mediterranean, or Southeast Asian descent, where hemoglobin variants are more common.
How to Improve Your A1C
Because A1C reflects a three-month average, small consistent changes tend to matter more than dramatic short-term efforts. Cutting refined carbohydrates, adding regular physical activity (even 30 minutes of brisk walking most days), and losing a modest amount of weight if you’re carrying extra pounds can each lower A1C by measurable amounts. People in the prediabetes range who make these changes often bring their numbers back below 5.7%.
If you’re managing diabetes with medication, A1C is the primary scorecard your healthcare provider uses to assess whether your current plan is working. A drop of even 0.5% reflects a meaningful improvement in average blood sugar and a real reduction in long-term complication risk. Most providers recheck A1C every three to six months, which gives enough time for changes in diet, exercise, or medication to show up in the results.