how to calculate a1c levels

The A1C test measures your average blood sugar levels over the past 2-3 months. It is expressed as a percentage, and the calculation is based on the amount of glucose attached to hemoglobin in your red blood cells. Here’s how it works:

• A1C Formula: The A1C percentage is calculated using the average blood glucose levels over time. The formula to estimate A1C from average blood glucose (in mg/dL) is:

  A1C (%) = (Average Blood Glucose + 46.7) / 28.7

• Example: If your average blood glucose is 154 mg/dL, your A1C would be:

  A1C = (154 + 46.7) / 28.7 = 7.0%

• A1C Ranges:

  • Normal: Below 5.7%
  • Prediabetes: 5.7% to 6.4%
  • Diabetes: 6.5% or above

• Note: The A1C test is performed in a lab or doctor’s office and does not require fasting. It provides a long-term view of blood sugar control, unlike daily glucose tests which give a snapshot of current levels.