For most adults with diabetes, a good A1c level is below 7%, which translates to an estimated average blood sugar of about 154 mg/dL. But “good” is genuinely personal here. Your ideal target depends on your age, how long you’ve had diabetes, whether you’re prone to dangerous blood sugar lows, and what other health conditions you’re managing. Some people should aim lower, and some are better off with a higher target.
What A1c Actually Measures
A1c reflects your average blood sugar over the past two to three months. It works by measuring how much glucose has attached to the hemoglobin inside your red blood cells. Since red blood cells live for roughly 70 days before your body replaces them, the test captures a rolling window of blood sugar exposure rather than a single snapshot.
This makes A1c fundamentally different from a finger stick or continuous glucose monitor reading. Those tell you what’s happening right now. A1c tells you the bigger picture. A single high or low day barely moves it, but weeks of consistently elevated blood sugar will.
How A1c Translates to Daily Blood Sugar
The percentage on your lab report can feel abstract. Here’s what common A1c values actually mean in terms of estimated average blood sugar:
- A1c 6%: ~126 mg/dL (7.0 mmol/L)
- A1c 7%: ~154 mg/dL (8.6 mmol/L)
- A1c 8%: ~183 mg/dL (10.2 mmol/L)
- A1c 9%: ~212 mg/dL (11.8 mmol/L)
- A1c 10%: ~240 mg/dL (13.4 mmol/L)
These are averages, though. Two people with the same A1c can have very different daily glucose patterns. One person might run steady at 154 mg/dL all day, while another swings between 80 and 230, landing at the same average. That’s one reason your care team looks at more than just A1c when evaluating your control.
The Standard Target: Below 7%
The most widely cited goal for adults with type 1 or type 2 diabetes is an A1c below 7%. This target comes from large studies showing that keeping A1c in this range significantly reduces the risk of complications affecting the eyes, kidneys, and nerves. An increase of roughly 1 percentage point in A1c is associated with a 37% higher risk of developing retinopathy or kidney disease.
Below 7% is where most people get the best balance between complication prevention and safety. Pushing much lower than that increases the risk of severe hypoglycemia, episodes where blood sugar drops low enough to cause confusion, seizures, or loss of consciousness. Severe low blood sugar events are themselves a strong marker of cardiovascular risk and death, so chasing an extremely low number can backfire.
When a Higher Target Makes Sense
A target of up to 8%, or even 8.5%, is appropriate for many people. This isn’t a failure. It’s a deliberate clinical choice based on the reality that aggressive blood sugar lowering carries real risks for certain groups.
Older adults fall into tiered categories. Those who are otherwise healthy with few other medical conditions generally aim for below 7.5%. People managing multiple chronic illnesses, or who have mild cognitive decline or difficulty with daily tasks, typically target below 8%. For those in poor overall health, living in long-term care, or dealing with advanced conditions like end-stage kidney disease or severe heart failure, the target relaxes to below 8.5%. At that point, the goal shifts from preventing complications decades away to avoiding dangerous blood sugar swings today.
The reasoning is straightforward: the benefits of tight control take years to materialize. If someone’s life expectancy is limited, they’ll experience the risks of intensive treatment (frequent lows, medication burden, falls) without living long enough to see the payoff. For adults over 80, or those with conditions like dementia or advanced cancer, some guidelines recommend not targeting a specific A1c number at all and instead focusing on keeping blood sugar from getting high enough to cause symptoms like excessive thirst, frequent urination, and fatigue.
When a Lower Target Is the Goal
Some people benefit from aiming tighter than 7%. If you’re relatively young, newly diagnosed with type 2 diabetes, and can reach a lower number without frequent low blood sugar episodes, your care team may encourage an A1c closer to 6.5% or even the normal range. The earlier in the disease you achieve good control, the longer the protective effects last.
Pregnancy is a special case. For women with pre-existing diabetes who are pregnant or planning to become pregnant, the ideal A1c is below 6% if achievable without significant hypoglycemia. Before conception, the target is below 6.5% to reduce the risk of birth defects, preeclampsia, and preterm delivery. If below 6% isn’t safely reachable during pregnancy, below 7% is the fallback.
Targets for Children and Teens
For children and adolescents with type 1 diabetes, the target has actually gotten more ambitious in recent years. The 2024 international guidelines recommend an A1c of 6.5% or lower for kids using advanced technology like continuous glucose monitors paired with automated insulin pumps. For those without access to that technology, the goal is 7% or below. These tighter targets reflect how much easier modern devices have made it to manage blood sugar safely in younger patients.
Time in Range: A Complementary Measure
If you wear a continuous glucose monitor, you’ve probably encountered “Time in Range,” the percentage of the day your blood sugar stays between 70 and 180 mg/dL. This metric is increasingly used alongside A1c because it reveals what the average hides, specifically how much you’re spiking after meals or dropping overnight.
The general target is 70% Time in Range, which corresponds roughly to an A1c of 7%. Hitting 50% Time in Range lines up with an A1c around 8%. Every 10% improvement in Time in Range (about 2.4 extra hours per day in the target zone) corresponds to roughly a 0.6% drop in A1c. That said, the correlation isn’t perfect. Two people at 50% Time in Range could have A1c values anywhere from 6.6% to 9.2%, depending on how high their highs go and how long they last.
Time in Range is especially useful for spotting patterns that A1c alone can’t reveal. You might have a “good” A1c of 7% but spend several hours a day above 250 mg/dL, balanced out by lows that pull the average down. That’s a very different situation from someone who genuinely stays in a narrow range most of the day.
How Often to Test Your A1c
If your blood sugar management is stable and you’re meeting your target, testing every six months is sufficient. If your treatment has recently changed, you’re not yet at your goal, or your blood sugar has been fluctuating due to lifestyle changes, testing every three months gives you and your care team enough data to adjust course. Children with type 1 diabetes and people planning pregnancy may need more frequent checks.
Keep in mind that certain conditions can skew A1c results. Anything that shortens red blood cell lifespan, like iron deficiency anemia, kidney disease, or recent blood loss, can make your A1c appear falsely low because your hemoglobin has less time to accumulate glucose. If your A1c doesn’t match what your daily readings suggest, that’s worth discussing with your provider.