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A1C to Average Glucose (eAG) Calculator

Convert an A1C percentage to its estimated average blood glucose (eAG) using the ADAG study's published formula, in mg/dL and mmol/L.

Estimated average glucose (mg/dL)
116.9 mg/dL
Estimated average glucose (mmol/L)
6.5 mmol/L
ADA/CDC A1C category
Prediabetes range

Where this falls

5.7 falls in the "Prediabetes range" range.

How it works

The A1C-Derived Average Glucose (ADAG) study found that A1C correlates linearly with the average blood glucose level over the prior roughly 2-3 months: eAG (mg/dL) = 28.7 × A1C(%) − 46.7. This is the same formula the American Diabetes Association's own eAG converter uses. The mg/dL result is also converted to mmol/L by dividing by 18.0182, the standard glucose unit conversion factor used worldwide outside the US.

The entered A1C is also categorized against the ADA/CDC's published diagnostic thresholds: below 5.7% is the normal range, 5.7% to 6.4% is the prediabetes range, and 6.5% or above is the diabetes range.

FAQ

Is this a diagnosis?

No. This is a published statistical estimate, not a measurement of your actual average glucose or a medical diagnosis. A1C results, especially near a threshold, should be interpreted by a healthcare provider alongside other factors.

Why doesn't eAG exactly match what my glucose meter shows?

eAG is a population-level regression estimate — real average glucose varies somewhat between individuals at the same A1C due to differences in red blood cell lifespan and other factors, which is exactly why the ADAG study reports it as an estimate (with an R² around 0.84) rather than an exact conversion.

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