A normal A1c is below 5.7%, which means your average blood sugar over the past two to three months has been in a healthy range. If you have diabetes, the general target is below 7%, though your ideal number depends on your age, health, and whether you’re pregnant. Understanding where you fall on this scale helps you gauge your risk and track your progress.
What the A1c Test Actually Measures
The A1c test measures the percentage of hemoglobin in your red blood cells that has glucose attached to it. Since red blood cells live for roughly two to three months, the test captures a rolling average of your blood sugar over that window rather than a single snapshot. This makes it more reliable than a finger-stick reading, which only tells you what’s happening right now. A higher percentage means your blood sugar has been running higher on average.
To make that percentage more intuitive, it converts to an estimated average glucose (eAG) in mg/dL using a simple formula. Here’s how common A1c levels translate:
- A1c 6%: average blood sugar of about 126 mg/dL
- A1c 7%: about 154 mg/dL
- A1c 8%: about 183 mg/dL
- A1c 9%: about 212 mg/dL
If your doctor gives you an A1c result and you want the eAG, multiply the A1c by 28.7 and subtract 46.7.
The Three A1c Categories
The National Institute of Diabetes and Digestive and Kidney Diseases uses three ranges to classify A1c results:
- Normal: below 5.7%
- Prediabetes: 5.7% to 6.4%
- Diabetes: 6.5% or above
A single test in the diabetes range isn’t enough for a formal diagnosis unless you already have clear symptoms like excessive thirst, frequent urination, or unexplained weight loss. Otherwise, a second test is needed to confirm.
If you land in the prediabetes range, your blood sugar is elevated but not yet high enough for a diabetes diagnosis. This is the stage where lifestyle changes, particularly losing 5% to 7% of your body weight and getting regular physical activity, have the greatest impact on preventing progression to type 2 diabetes.
Targets if You Have Diabetes
For most non-pregnant adults with diabetes, the widely recommended target is an A1c below 7%. That corresponds to an average blood sugar of about 154 mg/dL. Staying below this threshold significantly lowers the risk of complications affecting the eyes, kidneys, and nerves.
That said, 7% is a general guideline, not a universal rule. The 2025 American Diabetes Association Standards of Care recognize that targets should be personalized. Healthy older adults with few other chronic conditions are typically advised to aim for below 7% to 7.5%. For older adults at higher risk of dangerously low blood sugar (hypoglycemia), a looser target of below 8% is often more appropriate. Pushing too aggressively for a low number can cause frequent lows, which carry their own serious risks including falls, confusion, and cardiac events.
Your ideal target depends on several factors: how long you’ve had diabetes, what medications you take, whether you experience hypoglycemia, and what other health conditions you’re managing. A 35-year-old recently diagnosed with type 2 diabetes and no complications will generally have a tighter target than a 78-year-old with heart disease and a history of severe lows.
Targets During Pregnancy
Pregnancy calls for tighter blood sugar control because consistently elevated glucose can affect fetal development, especially during the first trimester when organs are forming. Most guidelines recommend an A1c of 6.5% or lower before becoming pregnant and below 6% during pregnancy itself.
These lower targets mean more frequent monitoring and often more intensive management. Blood sugar also behaves differently during pregnancy due to hormonal shifts, so the approach typically changes trimester to trimester. If you’re planning a pregnancy and have diabetes, getting your A1c into target range beforehand gives you the strongest start.
Targets for Children and Teens
The American Diabetes Association recommends an A1c of 7% or lower for all children and adolescents with diabetes. This applies across age groups, a shift from older guidelines that allowed higher targets for younger children. The reasoning is that tighter control during childhood reduces the cumulative years of elevated blood sugar and the long-term damage that comes with it.
Reaching this target in kids, especially those with type 1 diabetes, often involves continuous glucose monitors and insulin pumps, which have made tighter control more achievable without as many dangerous lows as older insulin regimens caused.
When A1c Results Can Be Misleading
The A1c test is considered the gold standard for assessing blood sugar control, but certain conditions can skew the results in either direction. According to the CDC, factors that can falsely raise or lower your A1c include:
- Severe anemia
- Kidney failure
- Liver disease
- Blood disorders like sickle cell anemia or thalassemia
- Certain medications, including opioids and some HIV drugs
- Blood loss or transfusions
- Early or late pregnancy
These conditions affect either how long your red blood cells survive or how hemoglobin behaves, which throws off the measurement. If any of these apply to you, your doctor may use alternative tests like fructosamine, which measures blood sugar over a shorter two-to-three-week window, or rely more heavily on daily glucose monitoring.
How Often to Get Tested
If you have diabetes and 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 are newly diagnosed, testing every three months gives a clearer picture of how things are trending. For people without diabetes who had a normal result, retesting every three years is typical unless risk factors change.
Because the A1c reflects a two-to-three-month average, testing more frequently than every three months won’t give you meaningfully new information. The results would overlap too much with the previous reading.