An A1C below 5.7% is considered normal for people without diabetes. If you have diabetes, the goal for most adults is an A1C below 7%, which translates to an average blood sugar of about 154 mg/dL. But “acceptable” depends heavily on your age, health status, and whether you’re pregnant, so the number your doctor targets for you may differ from someone else’s.
What A1C Numbers Mean
The A1C test measures the percentage of your red blood cells that have sugar attached to them. Because red blood cells live about three months, the test captures your average blood sugar over roughly the past two to three months, giving a much broader picture than a single finger-stick reading.
The diagnostic thresholds are straightforward:
- Normal: below 5.7%
- Prediabetes: 5.7% to 6.4%
- Diabetes: 6.5% or above
A single test result at or above 6.5% typically needs to be confirmed with a second measurement before a diabetes diagnosis is made, unless you already have obvious symptoms like excessive thirst, frequent urination, or unexplained weight loss.
Targets for Adults With Diabetes
The American Diabetes Association recommends an A1C below 7% for most non-pregnant adults with diabetes. That 7% corresponds to an estimated average glucose (eAG) of about 154 mg/dL, which is the same unit you see on a glucometer or continuous glucose monitor. Thinking about A1C in terms of eAG can make the number feel more concrete if you’re used to checking your blood sugar daily.
Some people can safely aim lower. If you’re younger, recently diagnosed, and managing your blood sugar without medications that cause low blood sugar episodes, a target closer to 6.5% may be reasonable. On the other hand, people who have had diabetes for many years, who take insulin, or who have a history of severe low blood sugar reactions often do better with a slightly higher target, sometimes up to 8%. The risk of dangerously low blood sugar increases as you push the A1C number down aggressively, and that risk isn’t always worth the benefit.
Different Goals for Older Adults
Age and overall health change the equation significantly. Tight blood sugar control takes about five years to produce measurable benefits in reducing complications like nerve damage or kidney disease. For older adults with limited life expectancy or significant frailty, the risks of aggressive glucose lowering (falls from dizziness, confusion from low blood sugar, functional decline) outweigh those long-term benefits.
European guidelines for elderly patients with type 2 diabetes recommend a target below 8% for those who are frail. For residents in care homes, particularly those with cognitive impairment or physical disabilities, the recommended ceiling is even more relaxed at 8.5%. Research has shown that keeping A1C below 7% in care-home residents did not protect them from complications like pneumonia, but did increase their risk of hypoglycemia and functional decline.
Targets During Pregnancy
Pregnancy calls for tighter control. The American College of Obstetricians and Gynecologists recommends that pregnant women with pre-existing type 1 or type 2 diabetes keep their A1C at or below 6%. High blood sugar during pregnancy increases the risk of birth defects, preeclampsia, and complications during delivery. A1C is typically checked every four to six weeks during pregnancy to track whether blood sugar management is on track.
Targets for Children and Teens
The American Diabetes Association recommends an A1C of 7% or lower for all children and adolescents with diabetes. This is the same general target as for adults, though hitting it can be more challenging during puberty, when hormonal changes make blood sugar harder to predict. Growth spurts, irregular eating patterns, and the emotional realities of managing a chronic condition as a teenager all play a role.
When A1C Results Can Be Misleading
A1C is reliable for most people, but certain conditions can push the number higher or lower than your actual blood sugar control would suggest. Since the test depends on hemoglobin in red blood cells, anything that changes how long those cells survive or how they’re structured can throw off results.
Conditions that shorten red blood cell lifespan, like hemolytic anemia or recovery from significant blood loss, will make your A1C falsely low. Your red blood cells simply haven’t been around long enough to accumulate sugar. Iron deficiency anemia has the opposite effect: it’s associated with higher A1C readings even when blood sugar is normal. This is particularly relevant in late pregnancy, where iron deficiency is common and can inflate A1C independent of actual glucose levels.
Genetic hemoglobin variants, which are more common in people of African, Mediterranean, and Southeast Asian descent, can also interfere with test accuracy depending on the laboratory method used. Chronic kidney disease and dialysis present another complication, as A1C tends to underestimate blood sugar levels in these patients. If any of these conditions apply to you, alternative markers like fructosamine or glycated albumin may give a more accurate picture of your blood sugar control.
What the Prediabetes Range Means
An A1C between 5.7% and 6.4% places you in the prediabetes range, which means your blood sugar is higher than normal but not yet high enough for a diabetes diagnosis. This is not a waiting room for inevitable diabetes. Roughly 70% of people with prediabetes will eventually develop type 2 diabetes, but lifestyle changes can dramatically reduce that risk. Losing 5% to 7% of your body weight and getting about 150 minutes of moderate physical activity per week have been shown to cut the progression rate nearly in half.
If your A1C falls in this range, it’s worth rechecking at least once a year. Small changes, even moving from 6.3% down to 5.9%, reflect real improvements in how your body handles sugar.