A normal A1C is below 5.7%. If you have diabetes, the recommended target is below 7% for most adults, though your ideal number depends on your age, overall health, and risk of low blood sugar. The A1C test measures your average blood sugar over the past two to three months, giving you a broader picture than any single glucose reading can.
The Three A1C Categories
The CDC uses these ranges to classify A1C results:
- Normal: below 5.7%
- Prediabetes: 5.7% to 6.4%
- Diabetes: 6.5% or above
These numbers translate roughly to average blood sugar levels. An A1C of 5.7% corresponds to an average glucose around 117 mg/dL, while 6.5% means your blood sugar has been averaging around 140 mg/dL over the past few months. A normal A1C of 4% to 6% maps to an average glucose of 70 to 126 mg/dL.
A1C Targets if You Have Diabetes
The American Diabetes Association recommends an A1C below 7% for most nonpregnant adults with diabetes. At that level, the estimated average glucose stays under 154 mg/dL, which substantially lowers the risk of complications affecting the eyes, kidneys, and nerves.
That said, 7% is not the right target for everyone. If you’re relatively young, recently diagnosed, and not experiencing episodes of low blood sugar, a tighter goal (closer to 6.5%) may be worth pursuing. The key requirement is that you can reach it safely, without frequent crashes in blood sugar that leave you shaky, confused, or unable to function.
On the other hand, a more relaxed target of up to 8% is reasonable if the risks of pushing lower outweigh the benefits. This applies when life expectancy is shorter due to advanced age or serious chronic illness, or when intensive treatment causes repeated episodes of dangerously low blood sugar. Pushing too hard toward a low number can be genuinely harmful in these situations.
How Targets Shift With Age
For older adults, the ADA breaks things into three health categories. Healthy older adults with few chronic conditions and intact thinking and physical ability can generally aim for the standard below-7% target. Those with multiple chronic illnesses, mild cognitive decline, or difficulty managing daily tasks on their own often do better with a less aggressive goal. And for people in long-term care or with advanced chronic disease, avoiding dangerously low blood sugar matters more than chasing a specific A1C number.
The concern with older adults is straightforward: low blood sugar episodes become more dangerous with age. A fall caused by dizziness from low blood sugar can lead to a hip fracture. Confusion from a glucose crash can mimic or worsen dementia. The goal shifts from preventing complications decades in the future to keeping someone safe and functional right now.
A1C Targets During Pregnancy
Pregnancy calls for tighter control. If you have diabetes and are planning to conceive, the ADA recommends getting your A1C below 6.5% before pregnancy to reduce the risk of birth defects, preeclampsia, and preterm delivery. Once pregnant, the ideal target drops further to below 6%, as long as you can maintain it without frequent low blood sugar. If that’s not achievable safely, the goal relaxes to below 7%.
What a Prediabetes A1C Means for You
An A1C between 5.7% and 6.4% places you in the prediabetes range. This isn’t a diagnosis of diabetes, but it signals that your blood sugar regulation is heading in the wrong direction. The U.S. Preventive Services Task Force recommends screening for prediabetes in adults aged 35 to 70 who are overweight or obese, and both lifestyle changes and medication have proven effective at slowing or preventing progression to diabetes.
Lifestyle interventions, meaning changes to diet and physical activity, are the first-line approach. Studies consistently show that modest weight loss (5% to 7% of body weight) combined with regular physical activity can dramatically reduce the odds of progressing from prediabetes to type 2 diabetes. If your A1C is in this range, the most useful thing you can do is treat it as an early warning rather than a diagnosis you’re stuck with.
How Often to Test Your A1C
Testing frequency depends on how well your blood sugar is controlled. If your A1C is above 7% or you’ve recently changed treatment, quarterly testing (every three months) produces the best results. Research in Diabetes Care found that testing every three months was associated with a 3.8% reduction in A1C, while annual testing actually corresponded with a slight increase. Testing more often than quarterly offered no additional benefit.
If your A1C has been stable and at goal for some time, testing twice a year is generally sufficient.
When A1C Results Can Be Misleading
The A1C test works by measuring how much sugar has attached to your red blood cells over their lifespan (about three months). Anything that changes how long your red blood cells live or how they behave can throw off the result.
Iron deficiency anemia can push A1C readings falsely high, which is particularly relevant for women during late pregnancy. Conditions that destroy red blood cells faster than normal, like hemolytic anemia, or recent significant blood loss will make A1C appear falsely low because the cells haven’t been around long enough to accumulate sugar. Sickle cell trait and other hemoglobin variants can also distort results depending on the testing method used. Kidney disease, especially in people on dialysis, tends to make A1C underestimate actual blood sugar levels.
If any of these conditions apply to you, direct glucose monitoring or alternative blood tests that measure sugar attached to proteins other than hemoglobin give a more accurate picture of your blood sugar control.