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HbA1c to Average Blood Sugar Converter

Enter either number. See the other, and what range it falls in.

Quick reference table

HbA1cAverage glucose (mg/dL)Average glucose (mmol/L)Category
5%975.4Normal range
5.7%1176.5Prediabetes range
6%1257Prediabetes range
6.5%1407.8Diabetes range
7%1548.6Diabetes range
8%18310.2Diabetes range
9%21211.7Diabetes range
10%24013.3Diabetes range

Conversion uses the ADAG study formula adopted by the American Diabetes Association.

Common questions

What does HbA1c actually measure?
HbA1c measures how much sugar has attached to the hemoglobin in your red blood cells, which is called glycated hemoglobin. Because red blood cells live about three months, the result reflects your average blood sugar over roughly the past three months. That makes it a bigger picture number than any single finger-prick reading.
What A1c level means prediabetes or diabetes?
An A1c from 5.7 to 6.4 percent falls in the prediabetes range, and 6.5 percent or higher on two tests is used to diagnose diabetes. Below 5.7 percent is considered normal. One result in the higher ranges does not settle it on its own, so confirm what your number means with your own doctor.
Why is my A1c different from my meter readings?
Your meter shows your blood sugar at one moment, while A1c averages every hour of the past three months, including nights and the hours after meals you never test. Conditions that affect red blood cells, such as anemia or kidney disease, can also push A1c up or down. If the two seem far apart, ask your doctor to help sort out which is telling the truer story.
How often should I have my A1c tested?
People with stable, well-controlled diabetes are usually tested twice a year. If your treatment has changed or your sugars are above target, every three months is common. People with prediabetes are often checked once a year, but your own doctor will set the right schedule for you.
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