A good A1C number is below 5.7%, which falls in the normal range and means your average blood sugar over the past two to three months has been healthy. If you already have diabetes, the goal shifts: most adults aim for an A1C below 7%, though your ideal target may be higher or lower depending on your age and overall health.
What A1C Ranges Mean
The A1C test measures the percentage of your red blood cells that have sugar attached to them. Since red blood cells live for about three months, the test captures a rolling average of your blood sugar rather than a single snapshot. The results fall into three categories:
- 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 is higher than normal but not yet in diabetic territory. Roughly one in three American adults falls into this category, and many don’t know it. The good news is that prediabetes is often reversible with lifestyle changes before it progresses.
What Your A1C Translates to in Daily Blood Sugar
A1C percentages can feel abstract. It helps to know what they mean in terms of the blood sugar readings you’d see on a glucose meter. The conversion follows a simple formula, and here are the key reference points:
- A1C of 6%: average blood sugar around 126 mg/dL
- A1C of 6.5%: around 140 mg/dL
- A1C of 7%: around 154 mg/dL
- A1C of 8%: around 183 mg/dL
- A1C of 9%: around 212 mg/dL
- A1C of 10%: around 240 mg/dL
So if your A1C is 7%, your blood sugar has been averaging roughly 154 mg/dL over the past few months. That context makes it easier to understand how daily choices are showing up in your results.
Targets for People With Diabetes
If you’ve already been diagnosed with diabetes, “good” doesn’t necessarily mean getting back below 5.7%. The American Diabetes Association recommends an A1C below 7% for most non-pregnant adults with diabetes. That target balances effective blood sugar control against the risk of pushing blood sugar too low, which carries its own dangers.
But this is one area where personal circumstances matter a lot. Recommended targets vary across four different ranges, from 6.0%–7.0% for healthier individuals to 8.0%–9.0% for people with shorter life expectancy or advanced diabetes complications. Older adults, people managing multiple chronic conditions, or anyone with a history of severe low blood sugar episodes may be better served by a slightly higher target. Younger, otherwise healthy adults may aim for something tighter. Your target should reflect a conversation with your care team, not a number pulled from a chart.
Targets During Pregnancy
Pregnancy calls for tighter control. Most guidelines recommend an A1C of 6.5% or lower before becoming pregnant to reduce the risk of complications, and below 6% during pregnancy itself. These stricter targets reflect the fact that high blood sugar in early pregnancy significantly raises the chance of birth defects and other problems. If you’re planning a pregnancy and your A1C is above 6.5%, working to bring it down beforehand gives you and your baby the best start.
How Much Lifestyle Changes Can Move Your A1C
Diet and exercise alone can meaningfully lower A1C, especially over time. A large review of lifestyle intervention studies found an average reduction of about 0.5 percentage points compared to standard care. That might sound small, but dropping from 7.5% to 7.0% moves you into target range and meaningfully reduces your risk of complications.
The effects get stronger the longer you stick with it. In the same review, people who maintained changes for four to six months saw about a 0.2 point drop, while those who kept going beyond 12 months saw a 0.8 point reduction. Programs that combined one-on-one coaching with group activities were the most effective, averaging nearly a full percentage point decrease. One study found that participants in a structured lifestyle program lowered their A1C from 6.65% to 6.34% over the course of the intervention, pushing some from the prediabetes range back into normal territory.
When Your A1C Might Not Be Accurate
The A1C test is reliable for most people, but certain conditions can skew results in ways that matter. Because the test depends on red blood cells, anything that changes how long those cells survive or how they’re structured can throw off the reading.
Iron deficiency anemia, which is especially common in women and during pregnancy, tends to push A1C results falsely higher. Treating the iron deficiency brings A1C readings back down, even without changes in actual blood sugar. On the other hand, conditions that shorten red blood cell lifespan, like recovery from significant blood loss or certain types of anemia where red blood cells break down faster than normal, will make A1C look falsely low.
People with sickle cell disease or other inherited hemoglobin variants face the most significant accuracy issues. For these individuals, alternative tests that measure sugar attached to blood proteins rather than red blood cells may give a more reliable picture. Late pregnancy can also affect accuracy due to iron changes, which is one reason glucose monitoring plays a bigger role than A1C during those months.
If you have any of these conditions and your A1C results don’t seem to match how you feel or what your daily glucose readings show, the discrepancy may be the test rather than your blood sugar control.
How Often to Get Tested
Testing frequency depends on where you stand. If you’re in the prediabetes range, once a year is typically enough to track whether things are stable or moving in the wrong direction. If you have diabetes that’s well controlled and you’re not on insulin, twice a year covers it. You’ll likely need more frequent testing if you use insulin, if your blood sugar has been difficult to manage, or if your treatment plan recently changed. Any time a new medication enters the picture, a follow-up A1C a few months later shows whether it’s working as expected.