Convert A1C percentage to estimated average glucose (eAG) and assess your diabetes risk. Understand your blood sugar levels with accurate ranges for normal, prediabetes, and diabetes.
Enter your A1C value (typically between 4% and 15%)
The A1C test (also called HbA1c or glycated hemoglobin) measures your average blood sugar levels over the past 2-3 months. It shows the percentage of hemoglobin proteins in your blood that are coated with sugar. This test is crucial for diagnosing and monitoring diabetes.
The estimated average glucose (eAG) can be calculated from your A1C percentage using these formulas:
mg/dL: eAG = (28.7 × A1C) - 46.7
mmol/L: eAG = (1.59 × A1C) - 2.59
Understanding where your blood sugar levels fall helps you assess your diabetes risk and take appropriate action:
A1C: Below 5.7%
Average Glucose: Below 114 mg/dL (6.3 mmol/L)
Your blood sugar levels are within the healthy range. Continue maintaining a balanced diet, regular exercise, and healthy lifestyle habits.
A1C: 5.7% to 6.4%
Average Glucose: 114-139 mg/dL (6.3-7.7 mmol/L)
Your blood sugar is higher than normal but not yet in the diabetes range. This is a critical time to make lifestyle changes to prevent or delay type 2 diabetes.
A1C: 6.5% or higher
Average Glucose: 140 mg/dL (7.8 mmol/L) or higher
Blood sugar levels are in the diabetes range. Consult with your healthcare provider for proper diagnosis, treatment plan, and ongoing management.
The A1C test provides valuable information that daily blood sugar checks cannot:
Unlike daily glucose tests that show a single moment in time, A1C reflects your average blood sugar over 2-3 months, providing a comprehensive view of your glucose control.
A1C is one of the primary tests used to diagnose prediabetes and type 2 diabetes. It's more convenient than fasting glucose tests as it doesn't require fasting.
For people with diabetes, A1C tests help assess how well treatment plans are working and whether adjustments are needed to medications or lifestyle.
Higher A1C levels are associated with increased risk of diabetes complications like heart disease, kidney disease, nerve damage, and vision problems.
Whether you have prediabetes or diabetes, these evidence-based strategies can help improve your blood sugar control:
How often you should get an A1C test depends on your diabetes status and how well controlled your blood sugar is:
Get tested every 3 years starting at age 45, or earlier if you have risk factors like obesity, family history, or sedentary lifestyle.
Test annually to monitor progression and assess whether lifestyle changes are effectively preventing diabetes.
Test every 6 months if your blood sugar is consistently meeting treatment goals and your treatment plan is stable.
Test every 3 months to closely monitor blood sugar control and assess the effectiveness of treatment adjustments.
Certain conditions can cause A1C results to be inaccurate or misleading:
If you have any of these conditions, discuss alternative testing methods with your healthcare provider, such as fructosamine or continuous glucose monitoring.
Daily blood sugar tests show your glucose level at a specific moment, while A1C reflects your average blood sugar over 2-3 months. Both are important: daily tests help you make immediate adjustments, while A1C shows overall control and long-term trends.
In rare cases, yes. Some people have normal A1C but high fasting glucose or glucose tolerance test results. This is why doctors may use multiple tests for diagnosis. Additionally, certain medical conditions can affect A1C accuracy.
Since A1C reflects 2-3 months of blood sugar levels, significant changes typically take at least 2-3 months to show. With consistent lifestyle changes or medication adjustments, many people can lower A1C by 0.5-2% within 3 months. However, the rate varies based on starting levels and individual factors.
For most adults with diabetes, the American Diabetes Association recommends an A1C target below 7%. However, targets may be individualized based on age, duration of diabetes, presence of complications, and risk of hypoglycemia. Some people may aim for 6.5% or lower, while others may have targets of 7.5-8%.
No, fasting is not required for an A1C test. This is one of its advantages over fasting glucose tests. You can have the test done at any time of day, regardless of when you last ate.