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eAG Calculator
Estimated Average Glucose (eAG) helps bridge the gap between HbA1c results (long-term control) and daily self-monitoring glucose levels.
By converting HbA1c into the same units used by patient glucose meters (mg/dL or mmol/L), eAG simplifies patient education and goal setting. This tool uses the formulas derived from the international ADAG (A1c-Derived Average Glucose) study.
Hemoglobin A1c
InputNGSP Percentage
Estimated Average Glucose
Calculated from A1c. You can also type here to reverse calculate A1c.
Formulas & Context
ADAG Study Formulas:
• eAG (mg/dL) = (28.7 × A1c) − 46.7
• eAG (mmol/L) = (1.59 × A1c) − 2.59
Why eAG? While HbA1c provides a percentage of glycated hemoglobin, patients often struggle to correlate “7.0%” with their glucometer readings. Knowing that an A1c of 7.0% equals an average glucose of 154 mg/dL makes the target more tangible.
Target Guidelines: The American Diabetes Association (ADA) generally recommends an A1c < 7.0% (eAG < 154 mg/dL) for non-pregnant adults, though targets should be individualized.
Clinical References
How to Use This Calculator
Follow these steps to convert between A1c and Glucose.
Input A1c
Enter the HbA1c percentage in the left column to see the estimated average glucose.
Reverse Calculation
Alternatively, enter a glucose value (mg/dL or mmol/L) in the right column to estimate the corresponding A1c.
Reset
Use the Clear button to reset all fields.
Frequently Asked Questions
Not always. Meters often capture fasting or pre-meal levels, missing post-meal spikes. eAG captures 24/7 exposure, so it may differ from the “average” shown on your glucometer.
Conditions that alter red blood cell turnover (anemia, kidney disease, pregnancy) or hemoglobin variants can make A1c (and thus eAG) less accurate.