A1c Formula
GaryTardiff posted:
I have seen several times on here where someone will say, "If you have an A1c of x.x that means that your average BG is xxx. What is the formula used to determine this?
DavidHueben responded:

You can go to the following web site and find an online calculator to convert the A1C to average plasma glucose:


mrscora01 responded:
There are two formulas that I have seen used.
The usual formula to estimate the relationship between A1c and mean plasma glucose was derived from the DCCT study.

That formula is:

Mean Blood Glucose = (A1c * 35.6) - 77.3

There is another, less cited formula that works better, at least for me. It is called "The Nathan Formula" it is:

Mean Plasma Glucose = (A1c * 33.3) -86

This formula yields a mean plasma glucose which comes much closer to what my meter's 30 day average has looked like.

There are also a number of different online calculators that you can find by googling.

GaryTardiff responded:
Well, I'd still love to know the formula used I found a great converter on the ADA site. Check it out http://www.diabetes.org/living-with-diabetes/treatment-and-care/blood-glucose-control/estimated-average-glucose.html
GaryTardiff replied to GaryTardiff's response:
Thanks for the info guys!!