A normal A1C is below 5.7%. If you already have diabetes, the target shifts higher, with most adults aiming for below 7%. Those two numbers anchor the conversation, but your ideal A1C depends on your age, health status, and whether you’re pregnant or managing other conditions.
What A1C Measures and Why It Covers Months
The A1C test measures how much sugar has attached to your red blood cells’ hemoglobin, the protein that carries oxygen through your bloodstream. Once sugar binds to hemoglobin, it stays there for the life of that red blood cell, roughly 120 days. That’s why a single A1C reading reflects your average blood sugar over the past two to three months rather than a snapshot of one morning. Unlike a fasting glucose test, you don’t need to skip meals or prepare beforehand.
You can translate an A1C percentage into an estimated average glucose (eAG) using a simple formula: multiply the A1C by 28.7, then subtract 46.7. So an A1C of 7% corresponds to an average blood sugar of about 154 mg/dL, while 5.7% translates to roughly 117 mg/dL.
The Three Diagnostic Ranges
If you don’t have a diabetes diagnosis and you’re trying to figure out where your result falls, the cutoffs are straightforward:
- Normal: below 5.7%
- Prediabetes: 5.7% to 6.4%
- Diabetes: 6.5% or above
A result in the prediabetes range means your blood sugar runs higher than normal but hasn’t crossed the diabetes threshold. This is the window where lifestyle changes, including weight loss, regular exercise, and dietary shifts, are most effective at preventing progression. About 70% of people with prediabetes eventually develop type 2 diabetes if nothing changes, so this range is a genuine warning signal rather than a “borderline” result to ignore.
Target A1C for Adults With Diabetes
Once you have diabetes, the goal is no longer to stay below 5.7%. Pushing blood sugar that low with medication increases the risk of dangerous drops (hypoglycemia). For most non-pregnant adults with type 1 or type 2 diabetes, the recommended target is below 7%. That level has been shown to significantly reduce the long-term risk of complications affecting the eyes, kidneys, and nerves.
Some people can safely aim lower. If you’re earlier in your diabetes course, managing well without medications that cause low blood sugar, or using a continuous glucose monitor that helps you fine-tune control, a target below 6.5% may be reasonable. The key is reaching that number without frequent lows or a heavy burden on your daily life.
Targets for Older Adults
A1C goals get more flexible with age, and health status matters more than the number on your birthday. The American Diabetes Association breaks this into three tiers:
Older adults who are otherwise healthy, with intact memory and the ability to manage daily tasks independently, generally aim for an A1C below 7% to 7.5%. Those dealing with multiple chronic conditions, some cognitive decline, or difficulty with daily activities typically have a more relaxed target of below 8%. For people with serious illness, significant cognitive impairment, or limited life expectancy, strict A1C goals often do more harm than good. The priority shifts to simply avoiding blood sugar swings that cause symptoms.
The logic is practical: tight blood sugar control pays off over years and decades. If someone is unlikely to live long enough to benefit from that payoff, the risks of aggressive treatment (falls from low blood sugar, medication side effects, the daily burden of monitoring) outweigh the gains.
Targets During Pregnancy
Pregnancy tightens the target considerably. For women with preexisting diabetes who are planning to conceive, the goal is an A1C below 7% before becoming pregnant, because the risk of birth defects rises with higher blood sugar in early pregnancy. Once pregnant, the target drops to below 6%, as long as that can be achieved without significant hypoglycemia.
Pregnancy itself naturally lowers A1C slightly because red blood cell turnover speeds up, so the test reflects a shorter window of time. This is one reason your care team will monitor blood sugar more frequently during pregnancy rather than relying on A1C alone.
Targets for Children and Teens
For most children and adolescents with diabetes, the target is below 7%, the same as adults. Kids who use continuous glucose monitors or advanced insulin pumps and can manage tighter control without frequent lows may aim for below 6.5%. On the other hand, children who can’t recognize or communicate symptoms of low blood sugar, or who don’t have access to monitoring technology, may have a slightly higher goal of below 7.5%.
Children with type 2 diabetes often have a target of below 6.5%, since the medications used for type 2 carry a lower risk of hypoglycemia than insulin-based regimens for type 1.
When A1C Results Can Be Misleading
The A1C test assumes your red blood cells live a normal lifespan. Several conditions break that assumption and can produce results that don’t match your actual blood sugar control.
Iron deficiency anemia tends to push A1C readings artificially high. Your red blood cells survive longer when you’re iron deficient, giving sugar more time to accumulate on hemoglobin. Iron supplementation can bring the number back down even if your blood sugar hasn’t changed. Conversely, conditions that destroy red blood cells faster, like hemolytic anemia or recovery from major blood loss, shorten their lifespan and make A1C appear falsely low.
Sickle cell trait and other hemoglobin variants can interfere with the test in either direction depending on the lab method used. Chronic kidney disease, particularly in people on dialysis, tends to make A1C underestimate true blood sugar levels. If you have any of these conditions, your care team may use alternative markers like fructosamine or glycated albumin, which measure sugar attachment to blood proteins with shorter lifespans and give a more accurate picture.
How Often to Test
If your diabetes is well controlled and your treatment hasn’t changed recently, testing every six months is generally sufficient. When you’re adjusting medications, not meeting your target, or going through a major health change, testing every three months gives a clearer picture of whether your plan is working. During pregnancy, testing may happen even more frequently.
For people without diabetes who had a normal result, retesting every three years is typical unless risk factors like obesity, family history, or a previous prediabetes reading suggest closer monitoring.