A normal A1C level is below 5.7%. This blood test measures your average blood sugar over the past two to three months, giving a broader picture than a single glucose reading. An A1C between 5.7% and 6.4% falls in the prediabetes range, and 6.5% or higher indicates diabetes.
What the Numbers Mean
The A1C test works by measuring how much sugar has attached to your red blood cells. Since red blood cells live for about three months, the test captures a rolling average of your blood sugar rather than a snapshot of one moment. That makes it useful both for diagnosing diabetes and for tracking how well blood sugar is being managed over time.
Here’s how the ranges break down:
- Below 5.7%: Normal. Your blood sugar has been in a healthy range.
- 5.7% to 6.4%: Prediabetes. Blood sugar is higher than normal but not yet in the diabetes range. This is the window where lifestyle changes can make the biggest difference.
- 6.5% or higher: Diabetes. A second test is typically done to confirm the diagnosis.
To put these numbers in more concrete terms, an A1C of 7% translates to an estimated average blood sugar of about 154 mg/dL. Each 1% change in A1C corresponds to roughly a 29 mg/dL shift in average blood sugar. So an A1C of 6% means your blood sugar has averaged around 126 mg/dL, while an A1C of 8% puts the average closer to 183 mg/dL.
Target A1C for People With Diabetes
If you’ve been diagnosed with diabetes, the goal isn’t necessarily to get your A1C back below 5.7%. For most nonpregnant adults, the recommended target is below 7%. That level is associated with significantly lower risk of complications like nerve damage, kidney disease, and vision problems, while still being achievable without excessive episodes of low blood sugar.
Your personal target may be higher or lower than 7% depending on your situation. Someone who is younger, recently diagnosed, and managing diabetes with diet or a single medication might aim for something closer to 6.5%. Someone who has had diabetes for decades, takes multiple medications, or has a history of dangerously low blood sugar episodes may be better served by a less aggressive target of 7.5% or even 8%.
Targets for Older Adults
Age and overall health play a major role in what A1C target makes sense. For otherwise healthy older adults with good cognitive function and few other chronic conditions, guidelines suggest an A1C below 7% to 7.5%. The logic is straightforward: these individuals still benefit from tighter blood sugar control and can safely manage the treatment required to get there.
For older adults dealing with multiple chronic illnesses, mild to moderate cognitive decline, or difficulty with daily activities, a target below 8% is more appropriate. At this stage, the priority shifts toward avoiding dangerous drops in blood sugar rather than hitting a strict number. Hypoglycemia in older adults can cause falls, confusion, and hospitalization, so the risks of aggressive treatment start to outweigh the benefits.
For those in very poor health or with severe cognitive impairment, strict A1C goals offer minimal benefit. The focus moves entirely to preventing symptoms, both from blood sugar that’s too high and too low, rather than chasing a specific percentage.
Targets During Pregnancy
Pregnancy calls for tighter blood sugar control than usual. For women with pre-existing diabetes who are planning a pregnancy, the goal is an A1C below 6.5% before conception. Higher levels at the time of conception are linked to greater risk of birth defects, preeclampsia, and preterm delivery.
Once pregnant, the ideal A1C target drops to below 6% if it can be reached without frequent low blood sugar episodes. When that’s not safely achievable, the target is relaxed to below 7%. A1C naturally trends slightly lower in pregnancy because of changes in blood cell turnover, which is one reason tighter targets are both possible and recommended during this period.
Targets for Children and Teens
For children and adolescents with type 1 diabetes, an A1C below 7% is appropriate for many, though targets should be individualized. Puberty, growth spurts, inconsistent eating patterns, and the practical challenges of managing diabetes during school all factor into what’s realistic. A child who is hitting 7.5% without frequent lows may be in a healthier place than one who reaches 6.8% but has regular episodes of dangerously low blood sugar.
When A1C Results Can Be Misleading
The A1C test is reliable for most people, but certain conditions can push results artificially higher or lower. Severe anemia, kidney failure, and liver disease all interfere with the test’s accuracy. Blood disorders like sickle cell disease or thalassemia affect the structure or lifespan of red blood cells, which directly skews the measurement. Blood transfusions, significant blood loss, certain medications (including some opioids and HIV drugs), and pregnancy can also distort results.
If you have any of these conditions, your doctor may rely more heavily on other methods to track blood sugar, such as a continuous glucose monitor or fructosamine test, which measures blood sugar over a shorter window of about two to three weeks. The A1C number itself isn’t wrong in the way a broken thermometer is wrong. It’s accurately measuring something, just not the thing it’s supposed to represent in your case.
How Often to Get Tested
If your blood sugar is well controlled and stable, testing twice a year is generally sufficient. If you’ve recently changed medications, aren’t meeting your target, or have just been diagnosed, testing every three months gives you and your doctor faster feedback on whether your current plan is working. Since the test reflects a two-to-three-month average, testing more frequently than every three months won’t give you meaningfully new information.
For people with prediabetes, annual testing helps track whether blood sugar levels are trending upward, staying stable, or improving with lifestyle changes. Even small reductions in A1C during the prediabetes stage, from 6.2% to 5.8%, for example, represent a meaningful shift in risk.