How to Calculate A1C from Blood Sugar
If you use a continuous glucose monitor (CGM) or test your blood sugar several times a day, your device likely provides an "Average Glucose" reading. You can use this average to estimate what your lab-tested A1C will be.
The Inverse ADAG Formula
Our calculator uses the scientifically validated inverse formula:
A1C (%) = (Average Glucose + 46.7) / 28.7
Is eA1C the same as a Lab Test?
While the estimation (sometimes called eA1C or GMI) is highly accurate, it is not a direct replacement for a clinical hemoglobin A1C lab test. Lab tests measure the actual glycation of hemoglobin, whereas this calculator estimates that process based on glucose levels.
Internal Link: Compare with GMI
For CGM users, the Glucose Management Indicator (GMI) is often a more accurate predictor of lab A1C than a simple average. Try our GMI Calculator here.
