A normal A1C is below 5.7%. If you already have diabetes, most guidelines recommend keeping your A1C under 7%, though your ideal number depends on your age, health status, and type of diabetes. Here’s what each range means and what target makes sense for different situations.
What the Numbers Mean
The A1C test measures the percentage of your red blood cells that have sugar attached to them. Because red blood cells live about three months, the result reflects your average blood sugar over roughly the past two to three months, not just a single moment. A higher percentage means your blood sugar has been running higher overall.
The three diagnostic categories are straightforward:
- Below 5.7%: Normal
- 5.7% to 6.4%: Prediabetes
- 6.5% or above: Diabetes
A single test isn’t enough for a diagnosis. Unless you already have obvious symptoms of diabetes, a second test is needed to confirm the result.
How A1C Translates to Daily Blood Sugar
The percentage can feel abstract, so it helps to know what it looks like on a glucose meter. An A1C of 7% corresponds to an estimated average blood sugar of about 154 mg/dL. At 9%, that average jumps to roughly 212 mg/dL. Each 1% change in A1C represents a shift of about 28 to 30 mg/dL in your daily average. If you track your blood sugar at home, comparing those readings to your A1C can reveal whether your meter checks are catching the full picture or missing highs and lows at other times of day.
Targets for Most Adults With Diabetes
The two major professional organizations in the U.S. set slightly different goals. The American Diabetes Association recommends an A1C below 7% for most nonpregnant adults with diabetes. The American Association of Clinical Endocrinology sets a tighter target of 6.5% or lower, but only for people who can reach it without serious risk of low blood sugar episodes.
That distinction matters. Pushing your A1C below 6% sounds appealing, but large clinical trials have shown that aggressive glucose lowering significantly increases the risk of severe hypoglycemia (dangerously low blood sugar) without reducing the risk of death. A major meta-analysis of intensive control trials found no mortality benefit and a clear increase in severe low blood sugar events. For most people, landing somewhere in the 6.5% to 7% range strikes the best balance between preventing complications and staying safe day to day.
A less strict target of 7% to 8% is appropriate if you have a history of severe low blood sugar episodes, difficulty recognizing when your blood sugar is dropping, advanced kidney disease, or multiple serious health conditions. The goal in those cases is to avoid the immediate danger of hypoglycemia, which can cause falls, confusion, seizures, and hospitalizations.
Targets During Pregnancy
If you have type 1 or type 2 diabetes and become pregnant, the target is tighter: an A1C no higher than 6%. High blood sugar during pregnancy raises the risk of birth defects, preeclampsia, and complications during delivery. The test is typically used alongside daily glucose monitoring to get a more complete view, since A1C alone can miss the sharp spikes after meals that matter most during pregnancy.
Targets for Children and Teens
The American Diabetes Association recommends an A1C of 7% or lower for all children and adolescents with diabetes. This is the same as the general adult target, a change from older guidelines that allowed higher numbers in younger kids. The shift reflects evidence that tighter control in childhood reduces the risk of complications later in life, especially with newer tools like continuous glucose monitors that make it easier to avoid dangerous lows.
Targets for Older Adults
Age alone doesn’t determine your A1C goal, but overall health does. An otherwise healthy 70-year-old might aim for the standard target below 7%. But for older adults dealing with frailty, cognitive decline, or multiple chronic conditions, a higher target is safer and more realistic.
For mild to moderate frailty, an A1C between 7% and 8% is generally appropriate. For severe frailty, a range of 7.5% to 8.5% is considered more protective because it reduces the risk of hypoglycemia, which is especially dangerous in people prone to falls or who may not recognize the warning signs of low blood sugar. In some cases, A1C testing itself becomes unreliable due to conditions like anemia or kidney disease, and doctors shift to monitoring random blood sugar readings throughout the day instead.
When the Test Can Be Inaccurate
A1C measures sugar on hemoglobin, so anything that changes your hemoglobin can skew the result. Sickle cell trait is the most well-known example. Depending on the lab method used, it can push results falsely high or falsely low. Other hemoglobin variants, like hemoglobin E, tend to produce artificially low readings. Elevated levels of fetal hemoglobin (which some adults carry) can also interfere with several common testing methods.
Iron-deficiency anemia, significant blood loss, recent blood transfusions, and advanced kidney disease can all distort A1C results. If you have any of these conditions and your A1C doesn’t match what your daily glucose readings suggest, a different type of blood sugar test may give a more accurate picture. This is worth raising with your doctor, because an artificially low A1C could mask blood sugar levels that actually need attention.
How Often to Test
If your diabetes is well controlled and you’re meeting your treatment goals, you’ll typically get an A1C test twice a year. If your treatment plan has recently changed, you’re not hitting your target, or your blood sugar has been unstable, testing every three months is more common. Since the test reflects a rolling average over the previous two to three months, testing more frequently than that wouldn’t add useful information.
For people with prediabetes, periodic A1C checks (often yearly) help track whether lifestyle changes are keeping blood sugar stable or whether it’s trending upward toward a diabetes diagnosis. Even small improvements matter in this range. Dropping from 6.3% to 5.9%, for example, moves you back into the normal category and meaningfully lowers your risk of progressing to type 2 diabetes.