A1C to Average Glucose Calculator
Estimate A1C to average glucose values for health, wellness, and lifestyle planning.
This A1C to average glucose calculator, or A1C calculator, converts an A1C percentage (a measure of blood sugar control over roughly the past 2-3 months) into estimated average glucose (eAG), expressed in the same units as a daily glucose meter reading.
Enter your A1C percentage, and the calculator returns your estimated average glucose.
Worked Calculation Examples
| Scenario | Result | Calculation Step |
|---|---|---|
| A1C of 7% | eAG ≈ 154 mg/dL | eAG = 28.7 × 7 − 46.7 = 200.9 − 46.7 = 154.2 mg/dL. |
| A1C of 9% | eAG ≈ 212 mg/dL | eAG = 28.7 × 9 − 46.7 = 258.3 − 46.7 = 211.6 mg/dL. |
The A1C to eAG Formula
The standard conversion formula is: eAG (mg/dL) = (28.7 x A1C) - 46.7. This formula was developed from a large clinical study correlating A1C percentages with average glucose readings from continuous glucose monitoring, giving a standardized way to translate between the two units.
Why A1C Reflects a Longer-Term Average
A1C measures the percentage of hemoglobin proteins in red blood cells that have glucose attached, and because red blood cells live for about 2-3 months, A1C reflects average blood sugar over that period rather than a single point-in-time reading like a finger-stick glucose test.
How to Use the A1C to Average Glucose Calculator
- Open the A1C to Average Glucose Calculator and enter the values requested in the input fields.
- Check the units, percentages, dates, or time periods before reading the answer.
- Review the instant result and adjust any value to compare another scenario.
- Use the formula, example, and FAQs below to understand how the a1c to average glucose calculator works.
Frequently Asked Questions
How do you convert A1C to average glucose?
Use the formula eAG (mg/dL) = (28.7 x A1C) - 46.7, a standardized conversion derived from a large clinical study correlating A1C with continuous glucose monitoring data.
What does an A1C of 7% mean in average glucose?
Using the standard formula, an A1C of 7% corresponds to an estimated average glucose of about 154 mg/dL.
Why is A1C different from a daily glucose reading?
A1C reflects average blood sugar over roughly the past 2-3 months (the lifespan of red blood cells), while a glucose meter or CGM reading shows blood sugar at a single point in time.
How do I use this a1c to average glucose calculator?
Enter the known values, review the units or settings, and the calculator updates the result instantly. The formula and example on this page show how the answer is produced.
What does the A1C to Average Glucose Calculator calculate?
Estimate A1C to average glucose values for health, wellness, and lifestyle planning. It is designed for fast browser-based calculations without sign-up, downloads, or manual spreadsheet setup.
What formula does this a1c to average glucose use?
The formula is: eAG (mg/dL) = 28.7 × A1C − 46.7. This conversion comes from the ADAG (A1c-Derived Average Glucose) study, published in 2008 by an international research group led by David Nathan, which correlated A1C values against continuous glucose monitoring data from over 500 patients across multiple countries. The study's findings led major diabetes organizations to begin reporting estimated average glucose alongside A1C on lab results, since eAG uses the same units as a home glucose meter, making it more intuitive for patients than the A1C percentage alone.
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Last updated: September 27, 2026.