A good A1C level for someone without diabetes is below 5.7%. If you have diabetes, the general target is below 7%, though your ideal number depends on your age, overall health, and risk of low blood sugar episodes. The A1C test measures the percentage of your red blood cells that have glucose attached to them, giving a snapshot of your average blood sugar over the past two to three months.
How the A1C Test Works
Glucose in your bloodstream naturally sticks to hemoglobin, the oxygen-carrying protein inside red blood cells. The more glucose circulating in your blood, the more hemoglobin gets coated. Since red blood cells live about three months before being replaced, measuring that glucose coating reveals your average blood sugar over that entire lifespan. That makes A1C far more useful than a single finger-stick reading, which only captures one moment in time.
The Standard A1C Ranges
Diagnostic thresholds, set by the National Institute of Diabetes and Digestive and Kidney Diseases, break down 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 hasn’t crossed the diabetes threshold. This is the window where lifestyle changes, particularly weight loss, increased physical activity, and dietary shifts, have the strongest evidence for preventing or delaying type 2 diabetes. A diabetes diagnosis typically requires confirmation with a second test unless symptoms are already obvious.
What Each A1C Number Means in Daily Terms
A1C percentages can feel abstract. Converting them to estimated average glucose (eAG) makes the number more concrete, since eAG represents what you’d see on a blood sugar meter averaged over months. The conversion formula is: (28.7 × A1C) − 46.7 = eAG in mg/dL.
- 6% A1C: ~126 mg/dL average
- 6.5%: ~140 mg/dL
- 7%: ~154 mg/dL
- 7.5%: ~169 mg/dL
- 8%: ~183 mg/dL
- 9%: ~212 mg/dL
- 10%: ~240 mg/dL
So the difference between a 7% and an 8% A1C is roughly 30 mg/dL in your day-to-day average. That gap matters: sustained averages above 154 mg/dL progressively raise the risk of damage to blood vessels, nerves, kidneys, and eyes over the years.
Targets for Most Adults With Diabetes
The American Diabetes Association recommends an A1C below 7% for most nonpregnant adults. This target balances meaningful protection against long-term complications with a manageable risk of hypoglycemia (dangerously low blood sugar). For people who can reach a lower number without frequent or severe low blood sugar episodes, a tighter goal may be appropriate. Conversely, if your current medications cause frequent lows, pushing hard toward 7% can do more harm than good.
Adjusted Goals for Older Adults
A1C targets shift as people age, largely because low blood sugar becomes more dangerous. A severe hypoglycemic episode in an older adult can cause falls, confusion, hospitalizations, and cardiac events. The 2024 ADA guidelines for older adults outline three tiers:
- Healthy older adults with few chronic conditions and good cognitive function: below 7% to 7.5%
- Adults with multiple chronic conditions or mild to moderate cognitive impairment: below 8%
- Adults in poor or very complex health, including those in long-term care or with severe cognitive decline: no fixed A1C target. The priority shifts to simply avoiding both dangerously low and symptomatically high blood sugar.
For anyone in the second or third category, lowering A1C aggressively provides minimal benefit and introduces real risk. Simplifying treatment regimens, especially complex insulin schedules, is often a better move than chasing a number.
Targets During Pregnancy
Pregnancy demands tighter blood sugar control because elevated glucose raises the risk of birth defects, preeclampsia, premature delivery, and high birth weight. The ADA recommends an A1C below 6% during pregnancy if it can be achieved without significant low blood sugar episodes. When that isn’t safely possible, the target relaxes to below 7%.
Before conception, the ideal is an A1C below 6.5% to reduce the risk of congenital anomalies. It’s worth noting that A1C naturally runs slightly lower during pregnancy due to faster red blood cell turnover, so the test can underestimate true glucose levels in later trimesters.
Targets for Children and Teens
For children and adolescents with type 1 diabetes, the International Society for Pediatric and Adolescent Diabetes recommends an A1C at or below 7% as the standard goal. Kids using advanced technology like continuous glucose monitors paired with automated insulin delivery systems can aim for 6.5% or lower, as long as reaching that target doesn’t add stress or reduce quality of life. The key constraint is the same as in adults: keeping low blood sugar episodes rare, with less than 4% of the day spent below 70 mg/dL.
When A1C Results Can Be Misleading
Several conditions can skew your A1C reading, sometimes significantly. Anything that shortens the lifespan of red blood cells, such as hemolytic anemia or recent major blood loss, will make your A1C appear falsely low because the cells haven’t been around long enough to accumulate glucose. Iron deficiency anemia pushes the result in the opposite direction, producing a falsely high reading.
Genetic hemoglobin variants, including sickle cell trait (HbS) and hemoglobin C trait (HbC), can interfere with certain testing methods. If you carry one of these variants, your results need careful interpretation. Kidney disease, particularly in people on dialysis, also distorts A1C. In those situations, alternative markers like glycated albumin or fructosamine provide a more reliable picture of blood sugar control.
If your A1C doesn’t match what you’re seeing on your glucose meter or continuous monitor, one of these interfering factors could be the reason.
How Often to Get Tested
If your blood sugar is stable and you’re meeting your treatment goals, testing twice a year is sufficient. If your treatment has recently changed or you’re not yet at your target, quarterly testing makes more sense, with additional checks as needed. People on intensive insulin regimens or those going through medication adjustments may need even more frequent monitoring to track progress and catch problems early.