A good A1C number is below 5.7%, which means your average blood sugar over the past two to three months has been in the normal range. If you already have diabetes, the general target shifts to below 7%. Where you fall between those numbers, and what your personal goal should be, depends on your health situation.
What the A1C Ranges Mean
The A1C test measures the percentage of your red blood cells that have sugar attached to them. Because red blood cells live for about three months, the test captures a rolling average of your blood sugar rather than a single snapshot.
The three main categories break down like this:
- Normal: Below 5.7%
- Prediabetes: 5.7% to 6.4%
- Diabetes: 6.5% or higher
A result in the prediabetes range doesn’t mean diabetes is inevitable. It means your blood sugar has been running higher than ideal and that lifestyle changes, particularly around diet and exercise, can often bring it back down before it progresses.
A1C Targets if You Have Diabetes
For most non-pregnant adults with diabetes, the recommended A1C target is below 7%. That number represents an average blood sugar of roughly 154 mg/dL. It’s the threshold where the balance between blood sugar control and the risk of going too low (hypoglycemia) works out best for most people.
Your doctor may set a tighter target, closer to 6.5%, if you’re younger, recently diagnosed, or managing diabetes with lifestyle changes alone. On the other hand, a more relaxed goal of 7.5% or even 8% can make sense for older adults, people who’ve had diabetes for many years, or anyone with a history of severe low blood sugar episodes. The “right” number is the one that keeps your blood sugar well controlled without causing dangerous drops.
What Each Percentage Point Means in Practice
A1C numbers can feel abstract. Translating them into average daily blood sugar makes them more concrete:
- A1C of 6%: Average blood sugar around 126 mg/dL
- A1C of 7%: Average blood sugar around 154 mg/dL
- A1C of 8%: Average blood sugar around 183 mg/dL
- A1C of 9%: Average blood sugar around 212 mg/dL
The difference between one percentage point may not sound like much, but it carries real weight. In a study of 251 people with diabetes, those who lowered their A1C by roughly 1% through regular aerobic exercise and strength training reduced their risk of diabetes-related complications affecting the eyes, kidneys, and nerves by 35%. Small, sustained improvements in blood sugar add up over years.
A1C Goals During Pregnancy
Pregnancy calls for tighter blood sugar control because elevated glucose raises the risk of complications for both the mother and baby, including preeclampsia, preterm birth, and the baby growing unusually large. For women with type 1 or type 2 diabetes who are planning a pregnancy, the goal is an A1C below 6.5% before conception.
Once pregnant, the ideal A1C target drops to below 6%, as long as that level can be reached without frequent low blood sugar episodes. If hypoglycemia becomes a problem, the target may be relaxed to below 7%. Women with gestational diabetes follow specific meal-by-meal blood sugar targets rather than relying solely on A1C.
When A1C Results Can Be Misleading
The A1C test is reliable for most people, but certain health conditions can push the result higher or lower than your actual blood sugar warrants. 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.
Conditions that shorten the lifespan of red blood cells, like hemolytic anemia or recovery from significant blood loss, tend to make A1C look falsely low. Your red blood cells haven’t been around long enough to accumulate sugar, so the test underestimates your true average. Iron deficiency anemia has the opposite effect, pushing A1C readings artificially higher even when blood sugar is well controlled.
Kidney disease complicates things further. Chronic kidney failure, which is common in people who’ve had diabetes for a long time, can cause chemical changes to hemoglobin that skew results. People on dialysis often see A1C readings that underestimate their actual blood sugar levels.
Certain inherited hemoglobin variants, including sickle cell trait and hemoglobin C trait, can also affect accuracy. If you have one of these conditions, your doctor may rely more heavily on direct blood sugar monitoring or alternative tests like fructosamine or glycated albumin, which measure blood sugar over a shorter window of about two to three weeks.
How to Improve Your A1C
If your number is higher than your target, the most effective changes are the ones that lower blood sugar consistently over weeks and months rather than on any single day. Regular physical activity is one of the most reliable tools. A combination of aerobic exercise (walking, cycling, swimming) and strength training several times per week has been shown to lower A1C by close to a full percentage point in some studies.
Dietary changes matter just as much. Reducing refined carbohydrates, eating more fiber, and spacing meals evenly throughout the day all help prevent the sharp blood sugar spikes that drive A1C upward. Losing even 5% to 7% of your body weight, if you’re carrying extra, can move the needle significantly for people in the prediabetes range.
A1C is typically rechecked every three months, which gives you a clear feedback loop. If lifestyle changes alone aren’t bringing your number down enough, medication can close the gap. The key takeaway is that A1C isn’t a fixed verdict. It’s a moving number that responds to what you do between tests.