Understand the importance of HbA1c (Hemoglobin A1c) & its role in monitoring blood sugar levels. Know A1c charts, tests, levels, & normal ranges. Diabetes is diagnosed when your HbA1C is 6.5% or above, indicating average blood glucose levels of 140 mg/dL or higher, or 7.8 mmol/L and above. Effective management is critical to reduce complications and improve health outcomes. The normal range for HbA1C levels is below 5.7%. A normal HbA1C level is below 5.7%. This test measures blood sugar with the aim of diagnosing diabetes. HbA1c is your average blood glucose (sugar) levels for the last two to three months. If you have diabetes, an ideal HbA1c level is 48mmol/mol (6.5%) or below. If you're at risk of developing type 2 diabetes, your target HbA1c level should be below 42mmol/mol (6%).