A good A1C for someone without diabetes is below 5.7%, which translates to an average blood sugar of roughly 117 mg/dL or less. If you already have diabetes, the target shifts: most non-pregnant adults aim for an A1C under 7%, though your ideal number depends on your age, health, and risk of low blood sugar episodes.
What the A1C 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 that window rather than a single moment in time. That makes it more useful than a finger-stick reading for understanding your overall blood sugar control.
The standard categories break down like this:
- Normal: below 5.7%
- Prediabetes: 5.7% to 6.4%
- Diabetes: 6.5% or above
If your result falls in the prediabetes range, it means your blood sugar is higher than normal but not yet high enough for a diabetes diagnosis. That’s a window where lifestyle changes (losing 5 to 7% of your body weight, increasing physical activity) can meaningfully lower your risk of progressing to type 2 diabetes.
A1C Targets if You Have Diabetes
The American Diabetes Association recommends an A1C below 7% for most non-pregnant adults with diabetes, as long as reaching that goal doesn’t cause frequent or severe episodes of low blood sugar. At 7%, your estimated average blood sugar is about 154 mg/dL. Dropping below that threshold reduces the long-term risk of damage to your eyes, kidneys, and nerves.
Some people may benefit from a tighter target, closer to 6.5%, while others do better with a more relaxed goal of 7.5% or even 8%. The decision hinges on several factors: how long you’ve had diabetes, what medications you take, whether you’re prone to dangerous blood sugar drops, and your overall health picture. A person diagnosed recently who manages their blood sugar with diet alone, for example, can often safely aim lower than someone who has had diabetes for decades and takes insulin.
How Goals Change With Age
For older adults, A1C targets are generally less aggressive. The American Geriatrics Society recommends 7% to 7.5% for older adults with a life expectancy greater than 10 years, and 7.5% to 8% for those with a life expectancy under 10 years or multiple complex health conditions. The reasoning is practical: the cardiovascular benefits of tight blood sugar control take roughly 10 years to materialize, and the risk of dangerous low blood sugar episodes rises with age and frailty. Pushing for a very low A1C in someone unlikely to see those long-term benefits creates risk without reward.
Children and adolescents with type 1 diabetes follow the same general under-7% target that adults do, though goals are individualized and reassessed as kids grow.
A1C During Pregnancy
Pregnancy calls for tighter control. For women with pre-existing diabetes who are planning to become pregnant, the goal is an A1C below 7% before conception, because high blood sugar in the earliest weeks raises the risk of birth defects. Once pregnant, the target drops to below 6%, as long as that can be reached without significant low blood sugar episodes. Pregnancy naturally lowers A1C slightly due to faster red blood cell turnover, which is one reason the threshold is set lower than it would be otherwise.
Converting A1C to Average Blood Sugar
If you check your blood sugar at home, it helps to know how your A1C translates to the daily numbers you see on your meter. The conversion follows a simple formula, but a quick reference is easier:
- A1C of 6%: average blood sugar of about 126 mg/dL
- A1C of 6.5%: about 140 mg/dL
- A1C of 7%: about 154 mg/dL
- A1C of 8%: about 183 mg/dL
- A1C of 9%: about 212 mg/dL
- A1C of 10%: about 240 mg/dL
Keep in mind these are averages. Two people with the same A1C can have very different daily patterns. One might have steady blood sugar hovering near 154 mg/dL, while another swings between 80 and 250 mg/dL. The A1C would look the same for both, which is why many clinicians also look at time-in-range data from continuous glucose monitors when available.
When and How Often to Test
If you have diabetes and your blood sugar is well controlled, you’ll typically get an A1C test twice a year. If you’ve recently changed medications, aren’t meeting your goals, or are newly diagnosed, expect to test every three months so your care team can see whether adjustments are working. For people without diabetes, A1C is often part of routine screening, especially after age 45 or if you have risk factors like obesity, a family history of diabetes, or a history of gestational diabetes.
When A1C Results Can Be Misleading
Because the test depends on red blood cells, anything that changes how long those cells survive can skew results. Iron-deficiency anemia, sickle cell trait, heavy bleeding, recent blood transfusions, and kidney disease can all push your A1C artificially higher or lower than your true average blood sugar. If you have any of these conditions, your doctor may rely more heavily on other measures, like fructosamine tests or direct glucose monitoring, to get an accurate picture.
Pregnancy also affects accuracy, as mentioned above. Even in healthy pregnancies, faster red blood cell turnover means A1C tends to read lower than expected relative to actual blood sugar levels.