A1c chart?

Hi all,
I am wondering if anyone can point me in the direction of a credible A1c chart. I am working hard to get my numbers down and thought I was in a pretty good place, and then my endo burst my bubble by giving me a completely different average (not a true lab test at this point, we were just discussing numbers via email). I guess the chart I googled (and the hundreds of others like it) was not very accurate. Any ideas on where I can get an accurate source for bg averages=A1c?

Here's mine with the guidelines that I use personally. It's pretty old and I haven't bothered to update it to the latest eAG guidelines. However, it has served me well for over a decade, enabled me to completely reverse my neuropathies, and I am currently off all meds except for insulin.

221-A1cConversionChart.png (89.7 KB)

Thanks! That's the chart I was using, but I think the new eAG must be lower, because those numbers are quite a bit different. A little disheartening that I wasn't making as much progress as I thought...

Depends on what ‘average’ you are talking about.

eAG is not the same average glucose level as the average of your readings on your meter. Because people with diabetes are more likely to check their blood glucose more often when they are low (for example, first thing in the morning and before meals), the average of the readings on their meter is likely to be lower than their eAG.

How about the ADA site?


Thanks! I like being able to put in a number and have it calculate for me. The nice thing about this ADA calculator is that you can run it both directions: A1c-eAG and reverse. I found one on the accu-check website but it only converted eAG to A1c.

When I get my A1c measure, the lab also reports the average (according to their measure of "average" for the result). If your numbers are "in a good place" the average on one test is meaningless in my opinion. I think the Mayo Clinic has an excellent one - http://www.mayoclinic.org/tests-procedures/a1c-test/basics/results/PRC-20012585

The above chart is based on the older data relating HbA1c and average blood sugars. As brboyer indicates this relationship was updated in 2008 based on the work of a group known as the ADAG study group and a basic table as well as a calculator can be found on the ADA site

I've always used the calculator on the BloodSugar101 website. I always look at my meter's 7 and 30 day averages and convert using this calculator before I get my A1c done. The prediction is often times accurate down to the tenth. If there is a discrepancy between the two averages the 7 day is usually the most accurate.

In theory A1c is a 3 month average but because not all red blood cells live 3 months the most recent readings carry a little more weight. I'm a T2 not on insulin and my readings tend to stay within a fairly narrow range, not sure if this would work with someone experiencing a wider range of readings. I tend to test 4 to 5 time a day unless my readings vary out of my usual range and I'm trying to figure out what is wrong.

Calculators are nice but require user input. A chart is easier-faster to use so I found one that should fit the bill. I may use the data from it myself and update my own ancient chart. Of course, I'll include both mg/dl and mmol/L values for the eAG so that it can be used universally. In the interim, go to this link:
The chart is printable or can simply be pasted into Paint or Word.

Here's a link to a converter that uses the most recent ADAG system.


Some of the earlier conversion charts are based on older and less reliable data. I find it irritating that they continue to circulate on the internet. I have to say that they often seem to turn up on site promoting the protagonisists of ultra-low carb diets. I suspect this may be because the older charts indicate much higher equivalent BGs than does ADAG for any given HbA1c (and thus make your control look worse). Nothing like playing fast and loose with the facts when you have a point to make!

How much different? Different labs A1C can vary from each other by up to 0.5%. e.g. if one lab is showing 6.0% A1C, then a different lab might show it to be 6.5%. (This is for NGSP-certified labs. If it is not a NGSP-certified lab, I suppose the variation could be even wider.)

If you were expecting 6.0% and get 12.0%, then that's more than can be explained by just a chart change or lab-to-lab variation.

If you were expecting 6.2% and got 6.4%, that's well within the lab-to-lab variation.

At least .5% difference, and that's a pretty big difference when you are trying to gain tight control and think you're at your target, when, surprise! you're still quite a ways off. I'm just talking about general a1c charts floating around the interwebs, not labs or doctors office tests specifically. I'm inputting my dexcom/meter averages into those charts and apparently they are outdated.