Understanding blood sugar since 2011
percent (%)
mg/dL
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Enter your A1C or eAG to see your range.

Type in either field — the other will update automatically.

How this conversion works

The formula used here is the ADAG (A1C-Derived Average Glucose) equation, established by Nathan and colleagues in 2008 and adopted by the American Diabetes Association as the standard for translating A1C into an estimated average glucose value:

eAG (mg/dL) = (28.7 × A1C) − 46.7

The mmol/L equivalent is simply mg/dL divided by 18 (rounded). For example, an A1C of 7.0% corresponds to an eAG of 154 mg/dL, or 8.6 mmol/L. The relationship is linear: each 1% increase in A1C corresponds to roughly 29 mg/dL or 1.6 mmol/L of average blood glucose.

What this number means

A1C and eAG represent the same underlying information — your average blood sugar over the previous 2–3 months — just in different units. A1C is a percentage of glycated hemoglobin in your red blood cells. eAG translates that percentage into the same mg/dL or mmol/L numbers you see on a glucose meter or CGM.

For some people, eAG is easier to interpret because it speaks the same language as daily glucose readings. A1C of 7% sounds abstract; 154 mg/dL is a number you might actually see when you finger-stick.

Reference ranges

Category A1C eAG (mg/dL) eAG (mmol/L)
NormalBelow 5.7%Below 117Below 6.5
Prediabetes5.7% – 6.4%117 – 1376.5 – 7.6
Diabetes6.5% and above140 and above7.8 and above
Common diabetes targetBelow 7%Below 154Below 8.6

Individual targets vary — your healthcare provider may set a different goal depending on your age, other health conditions, and treatment plan.

When this conversion can be unreliable

The A1C-to-eAG relationship works well for most people, but certain conditions can make A1C a less accurate reflection of average glucose:

If you have any of these conditions, talk to your provider about the best way to monitor your blood sugar — a continuous glucose monitor may give you a more accurate picture than A1C alone.

Related

A note on this tool. This calculator uses the standard ADAG formula and provides a mathematical estimate, not a medical diagnosis. Your actual average glucose may differ from the calculated eAG, and your A1C may not reflect your true average if you have certain health conditions. Always discuss your numbers with a healthcare provider.