Welcome to my HbA1c converter spreadsheet page

Here you can download the spreadsheet to calculate your HbA1c percentage by using the average of your blood glucose levels. The creator of the spreadsheet is not a healthcare professional and does not in any way warrants the usability, performance or anything about this spreadsheet. Any damages resulting from the use of this spreadsheet will be limited to the amount of money that you paid me for it.

Before downloading the spreadsheet on the right, please read the FAQ. If you still have questions, I can be reached here I would recommend that you put "diabetes" as part of your message subject so that I don't dismiss it as spam. I can not promise that I will answer, but I will try. You will need Microsoft Excel to work with this spreadsheet.

Update February 7,2012

Eight years later, my HbA1c remains under control with the help of medication.

I uploaded a new version of the spreadsheet since it has been many versions of Excel since I originally created this. The page will remain here for as long as I have my website running so feel free to share.

Update November 19, 2003

Well, I finally visited my endocrinologist and got my results from my last week's HbA1c test. The good news is that the test result was 6.3%, which is better than I expected and it is a big improvement over the double digits that showed up when I was diagnosed in July. The other news is that the spreadsheet seems to be doing a half decent job of predicting the HbA1c since the data that I was able to collect before the test (96 Days and 218 different tests) predicted an HbA1c of 6.43%.

I uploaded a new version of the spreadsheet, this one has space for 120 days and I changed the conditional formatting a bit. The file is called BVG2.xls and is available to download. If you don't want to open it in the browser, you can always (right click / save as).

The HbA1c converter FAQ

1) Why did you do this:

I was recently diagnosed with diabetes and after reading the newsgroups about the importance of keeping control of blood sugars, I decided to keep track of my readings and come up with an estimated HbA1c. The main reason was that there is so much research out there mentioning the importance of keeping your HbA1c under 6.5% and most people have to wait to see their doctors in order to get the test done. I am aware that there are a couple of home tests, but they cost around US$30 each so I figured this would keep me sane until the next visit to the doctor.

2) How do I know your estimate is my correct HbA1c?

Well, I am certain that my estimate is not your actual HbA1c number. This is only an estimate and not a very good one at that. Before you start picking it apart, let me do some of the work for you. First, this model does not properly assign weights to the different measurements. For example, if you measure your blood glucose one hour after lunch you will have a high number, but this number might be short-lived. On the other hand, if you measure before going to bed and get a low number and this number lasts during the whole night the model gives each one of them the same importance. I also had trouble defining what span of time the HbA1c test reflects. A lot of the literature out there mentions that HbA1c reflects the last three months of average blood glucose levels, while newer studies show that the number might be as low as four weeks. My solution: I made enough space for 100 days of measurement. If you want to compute only four weeks, then only use 28 days.

3) Have you tested this? What formula are you using?

I have not had a chance since I have only been diagnosed for less than three months. The formula I am using is one that I came up with using the Nathan formula to calculate average blood glucose level from HbA1c that I found in the internet. Since I wanted to calculate HbA1c and I had the information about my blood glucose levels, I just used some high-school algebra to work it back. As you can see, I was wrong when I said that I would never use that stuff in real life. The actual formula is (Average mg/dl + 86) / 33.3

4) You are so lazy, I measure my BG ten times a day, you only do it five times. Can you make it so that I can use all my data?

The more data you have, the better your average will be and therefore the better the model should work in theory. In order to use more data, some colums need to be added. I am using five colums because I try to at least do those five tests if I have the time. I have also done more than five tests in a day after a really high blood glucose number, but did not use that information since it might affect the outcome. Also note that another fault of the model is that some days only have one result, while others might have all five. What can I say, the whole thing is imperfect.

5) This is a horrible waste of binary space in my hard drive. Just looking at it has made my blood sugar go up. If I could, I would take my toothbrush and physically brush the interiors of my computer to clean even the memory of its existance in my system. I could do this much better.

Feel free to take this idea and run with it as long as wathever product or spreadsheet you come up with is made available to the public free of charge. I am in no way a great Microsoft Excel user. I am sure people can make this better so please do so. If you want to do changes to it and want to put your version in an internet server, I can upload it here and give you credit as the creator. You can contact me Here

6) Why are some of my readings highlighted?

I use that to remind me about when I have been bad. There is a way to do a cell format in excel called conditional formatting. I set it to highlight any number above 130. If you have better control, you could change it to a lower number. If you don't, then change it to a higher number. You could also disable the formatting. But I thought it was neat.

Here are some books from Amazon that might help you with controlling it: Diabetes Diet: The 101 Best Diabetic Foods
Dr. Neal Barnard's Program for Reversing Diabetes: The Scientifically Proven System for Reversing Diabetes without Drugs

Version 3.0 Release date February 7, 2012

Download version 3.0 of the spreadsheet
Click here to download version 3.0 of the spreadsheet

Version 2.0 Release date November 19, 2003

Download version 2.0 of the spreadsheet
Click here to download version 2.0 of the spreadsheet

Version 1.0 Release date September 24, 2003

Download version 1.0 of the spreadsheet
Click here to download version 1.0 of the spreadsheet

Feel free to visit my Commercial loan advice website if you need some feedback on that topic.