An ideal A1c level for most adults is below 5.7%, which indicates normal blood sugar control over the past two to three months. If you already have diabetes, the target shifts: most guidelines recommend keeping your A1c below 7%, though your personal goal may be higher or lower depending on your age, health, and risk of low blood sugar episodes.
What the A1c Test Measures
The A1c test (also called hemoglobin A1c or HbA1c) measures the percentage of your red blood cells that have glucose attached to them. Because red blood cells live for about three months, the test captures your average blood sugar over that window rather than a single moment in time. That makes it more useful than a finger-stick reading for understanding long-term blood sugar trends.
An A1c of 7% translates to an estimated average glucose of about 154 mg/dL. As your A1c rises or falls by a single percentage point, your average daily blood sugar shifts by roughly 29 mg/dL in either direction. So the difference between an A1c of 6% and 8% represents a meaningful gap in how much sugar is circulating through your bloodstream day after day.
Normal, Prediabetes, and Diabetes Ranges
The CDC uses three A1c categories for diagnosis:
- Normal: below 5.7%
- Prediabetes: 5.7% to 6.4%
- Diabetes: 6.5% or higher
If your result falls in the prediabetes range, it means your blood sugar has been running higher than normal but hasn’t crossed the diabetes threshold. This is a window where lifestyle changes, particularly losing 5 to 7% of body weight and getting regular physical activity, can delay or prevent the progression to type 2 diabetes. About one in three American adults has prediabetes, and most don’t know it because the condition produces no obvious symptoms.
Targets for People With Diabetes
Once you have a diabetes diagnosis, “ideal” no longer means getting back below 5.7%. It means finding the lowest A1c you can safely maintain without frequent drops in blood sugar. The two major U.S. guidelines differ slightly on where that target sits.
The American Diabetes Association (ADA) recommends an A1c below 7% for most nonpregnant adults with diabetes. The American Association of Clinical Endocrinologists (AACE) sets a tighter goal of 6.5% or below, but only for people without serious coexisting illnesses and who are at low risk for hypoglycemia. Both organizations agree that for people with a history of severe low blood sugar episodes, advanced kidney disease, multiple chronic conditions, or long-standing diabetes that has been hard to control, a less aggressive target of 7% to 8% is more appropriate.
The reason for this flexibility is straightforward: pushing A1c too low with medication can trigger dangerously low blood sugar, which carries its own serious risks, including confusion, falls, seizures, and heart problems. The goal is always a balance between reducing the long-term damage from high blood sugar and avoiding the short-term danger of going too low.
Targets for Children and Teens
For children and adolescents with type 1 diabetes, the ADA recommends an individualized A1c goal, noting that a target below 7% is appropriate for many young patients. In practice, hitting that number is harder during the teenage years because of hormonal changes, growth spurts, and the practical challenges of managing insulin through a busy school and social life. Pediatric targets are reassessed over time as the child’s needs and self-management abilities change.
Targets During Pregnancy
Pregnancy demands tighter blood sugar control than usual. When A1c rises above 8% early in pregnancy, the risk of miscarriage and problems with fetal organ development increases significantly, and that risk climbs progressively as A1c goes higher. Most clinicians aim for an A1c as close to normal as possible before conception and during the first trimester, typically below 6.5%, while balancing the risk of hypoglycemia. Blood sugar targets are often tracked with frequent daily glucose monitoring rather than relying on A1c alone, since the test’s three-month average can mask the rapid shifts that matter most during pregnancy.
Targets for Older Adults
For older adults, especially those dealing with frailty or multiple health conditions, the ideal A1c is intentionally higher than the standard 7% target. Guidelines from the Association of British Clinical Diabetologists recommend a range of 7% to 8% for older adults with mild to moderate frailty, and 7.5% to 8.5% for those with severe frailty.
In frail older adults, an A1c below 7% is actually considered a red flag for overtreatment. At that level, blood sugar may be dipping low enough to cause falls, confusion, or cardiovascular strain. If you’re caring for an older parent or relative with diabetes and their A1c comes back below 7%, it’s worth asking whether their medication needs to be scaled back rather than celebrated as good control.
Why Your A1c Might Not Be Accurate
The A1c test assumes your red blood cells have a normal lifespan of about three months. Several conditions can throw off that assumption and produce a misleading result. Iron-deficiency anemia, sickle cell disease or trait, thalassemia, recent blood loss, blood transfusions, and chronic kidney disease can all cause your A1c to read falsely high or falsely low. If you have any of these conditions, your doctor may use a different test, such as fructosamine, or rely more heavily on direct glucose monitoring to assess your control.
A1c Versus Continuous Glucose Monitoring
A1c gives you a single average, but it can’t tell you how much your blood sugar swings throughout the day. Two people can have the same A1c of 7% while living very different realities: one might have stable glucose hovering near 154 mg/dL, while the other bounces between 60 and 300 mg/dL multiple times a day. The second person faces greater risk despite the identical A1c.
This is where continuous glucose monitors (CGMs) add a layer of insight. The metric most commonly used with CGMs is “time in range,” which measures the percentage of the day your blood sugar stays between 70 and 180 mg/dL. An A1c of 7% roughly corresponds to spending about 60 to 65% of the day in range, depending on the type of CGM used. Increasing your time in range improves outcomes even if your A1c doesn’t budge much, because it means fewer dangerous highs and lows. Many people with diabetes now track both numbers to get a fuller picture of their glucose control.
How to Lower Your A1c
Small, sustained changes tend to matter more than dramatic short-term efforts. For people with prediabetes or early type 2 diabetes, the most effective strategies are consistent physical activity (150 minutes per week of moderate exercise like brisk walking), reducing refined carbohydrates, and modest weight loss. Losing even 5% of your body weight can meaningfully lower your A1c.
For people already on diabetes medication, A1c improvements often come from tightening up the basics: taking medications consistently, monitoring blood sugar to understand how specific foods affect you, managing stress, and getting enough sleep. Poor sleep and high stress hormones both raise blood sugar independently of diet. Each full percentage point you drop your A1c, say from 8% to 7%, substantially reduces your risk of damage to your eyes, kidneys, and nerves over the following years.
A1c is typically rechecked every three months when treatment is being adjusted and every six months once levels are stable. Because the test reflects a rolling average, changes you make today won’t fully show up in your A1c for about two to three months.