A1C to Average Blood Glucose Calculator
A1C to Average Blood Glucose Calculator
Convert Between A1C and eAG
From A1C
From Average Glucose
Estimated Average Glucose
Enter a value to convert.
Understanding A1C and Average Glucose
A1C measures the percentage of hemoglobin coated with glucose, reflecting average blood sugar over roughly the past 2-3 months. Estimated Average Glucose (eAG) translates that percentage into the same mg/dL units used by a daily glucose meter, making the two numbers easier to compare.
The ADAG Formula
eAG (mg/dL) = 28.7 × A1C − 46.7, derived from the A1C-Derived Average Glucose (ADAG) study that linked A1C to continuous glucose monitoring data.
A Longer-Term Average
Unlike a single fingerstick reading, A1C reflects a rolling ~3-month average -- useful for tracking overall trends rather than moment-to-moment swings.
Works in Both Directions
Convert an A1C lab result into a familiar mg/dL number, or convert a meter's average reading back into an approximate A1C.
Reference, Not Diagnosis
This calculator is an educational conversion tool -- diagnosis and treatment decisions belong with your healthcare provider.
Worked Example
Suppose your A1C result is 7.0%:
- eAG: 28.7 × 7.0 − 46.7 = 154.2 mg/dL.
- In mmol/L: 154.2 ÷ 18.0 ≈ 8.6 mmol/L.
Result
- eAG: 154.2 mg/dL
- In mmol/L: 8.6
Key Takeaways
- General Ranges: Below 5.7% is typically considered normal, 5.7-6.4% prediabetes, and 6.5%+ diabetes -- always confirm with a clinician using current guidelines.
- An Average, Not a Peak: eAG doesn't capture how much your glucose swings day to day -- two people with the same A1C can have very different variability.
- Educational Only: Use this to understand lab results, not to self-diagnose or adjust medication.