This all-in-one online A1C Calculator converts the result of a hemoglobin A1C test (HbA1c) into average blood sugar level or vice versa. You can enter the value of the known parameter in the respective input field of this calculator and find the missing parameter.
What A1C Means
The A1C test — also known as the hemoglobin A1C or HbA1c test — is a simple blood test that measures your average blood sugar levels over the past 3 months. It’s one of the commonly used tests to diagnose prediabetes and diabetes, and is also the main test to help you and your health care team manage your diabetes
When sugar (glucose) enters your bloodstream, it attaches to hemoglobin, a protein found inside red blood cells (erythrocytes) that carry oxygen to all of the cells in your body.
Everybody has some sugar attached to their hemoglobin. But the higher your blood glucose, the more sugar-coated or “glycated” the hemoglobin becomes.
The A1C test measures the percentage of your red blood cells that have sugar-coated hemoglobin. Since the life cycle of the erythrocyte is about four months, the A1C percentage reflects the average blood sugar level detected on hemoglobin in cells of different ages.
According to the CDC, a normal A1C level is below 5.7%. The levels from 5.7% to 6.4% indicate prediabetes. Those with levels from 6.5% and above are considered to have diabetes.
The study by Nathan et al. showed a mathematical relationship between A1C and average blood sugar (glucose) levels:
Average Blood Sugar (mg/dL) = 28.7 * A1C(%) – 46.7.
Using this formula, you can calculate the average blood sugar level if you know A1C. On the other hand this is how A1C is calculated when the average blood sugar level is known. All calculations performed by our A1C calculator are based on this formula.
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Disclaimer. This calculator is not a replacement for an A1C lab test or for clinical judgment. In case of any concerns please consult your physician to address your specific health problem.