📈 Estimated Average Glucose Calculator
Translate HbA1c lab results into everyday glucose numbers and plan your diabetes management.
Use the lab-reported HbA1c percentage. Most diabetes guidelines target < 7% for many adults.
Formula: eAG (mg/dL) = 28.7 × HbA1c − 46.7 • mmol/L conversion uses factor 18.0182.
How to Use This Calculator
Select your conversion direction
Choose between converting an HbA1c lab result to eAG or translating your eAG back to an estimated HbA1c.
Enter the source value
Provide either your HbA1c (%) or eAG (mg/dL) and click calculate to see the converted numbers.
Discuss the result with your care team
Use the eAG value to understand your daily glucose patterns and collaborate with your clinician on treatment changes.
Formula
The A1c-Derived Average Glucose (ADAG) equation connects long-term glycemic exposure with daily glucose readings. Use these formulas:
- eAG (mg/dL) = 28.7 × HbA1c − 46.7
- eAG (mmol/L) = (28.7 × HbA1c − 46.7) ÷ 18.0182
- Estimated HbA1c (%) = (eAG (mg/dL) + 46.7) ÷ 28.7
These relationships were validated in the New England Journal of Medicine (2008) ADAG study, correlating continuous glucose monitoring with HbA1c results across diverse populations.
Full Description
HbA1c reflects the percentage of glycated hemoglobin and represents approximately three months of average blood glucose. Many patients find it easier to interpret everyday glucose values, which is why laboratories now often report eAG alongside HbA1c.
This calculator lets you perform that conversion instantly and see the result in both mg/dL and mmol/L. It is particularly useful when comparing lab results with readings from home glucose meters or continuous glucose monitoring (CGM) systems.
Note that factors such as anemia, hemoglobin variants, or recent transfusions can skew HbA1c results. In such cases, clinicians may rely more on CGM metrics like time-in-range rather than eAG alone.
Frequently Asked Questions
Is eAG the same as average meter readings?
eAG approximates the mean glucose over three months, similar to meter averages if you test regularly. However, it may differ if you only check at certain times of day or have significant glucose variability.
Why do guidelines use HbA1c instead of eAG?
HbA1c remains the gold standard for diagnosing and monitoring diabetes. eAG is a supplementary translation to make the numbers more relatable for everyday management.
Can kidney disease affect the conversion?
Advanced kidney disease can alter red blood cell turnover and HbA1c accuracy. Discuss alternative markers such as fructosamine with your nephrologist or endocrinologist.
What eAG corresponds to an HbA1c of 7%?
An HbA1c of 7% equals an estimated average glucose of approximately 154 mg/dL (8.6 mmol/L).
Does eAG account for time in range?
No. eAG is a single mean value. For a fuller picture, review time-in-range, time-below-range, and glucose variability metrics from your CGM reports.