I do have the actual Formula on my phone but unfortunately that has gone away for repair. In any case I always use this Convertor from our own Community pages :
I tried the convertor,, and seemed to get the same HbA1C over quite a wide range of average BG. Mind you, as I live between health authorities, my GP being in one, and the hosp being in another, last year I had my HbA1C taken by each health authority on the same day. (different arms, 2 hours apart) my results were 7.1 at one, and 7.4 at the other...so maybe the convetor is accurate enough?
Your calculator gives HbA1c as 6 for 5.5mmol/l average whereas mine gives HbA1c 5.27 for 5.5mmol/l average. How do we know which one's right :?: That is assuming I am using them correctly. :? Mine seems more like the result I was expecting judging from my previous test.
I too would use a calculator/convertor but here's the formula adapted from the ADA one. As far as I know this is the only formula based on recent worldwide evidence.
(though you're supposed to use it the other way round from Hb A1c to estimated average glucose level)
(average glucose in mmol/l x18) + 46.7
...................28.7
Sorry about the extra dots, it's the only way I could get the 28.7 into the 'right' place! http://professional.diabetes.org/GlucoseCalculator.aspx
edited to add that it's only ever an estimate; depends on the length of time your red blood cells last, whether you're a 'high' or 'low 'glycator and pragmatically Its only going to have any semblance of accuracy if you measure your glucose levels several times a day. When they were investigating the relationship between average levels and HbA1c, the subjects were doing 6 or 7 readings a day and some of them wore continuous monitors for a period.
Your calculator gives HbA1c as 6 for 5.5mmol/l average whereas mine gives HbA1c 5.27 for 5.5mmol/l average. How do we know which one's right :?: That is assuming I am using them correctly. :? Mine seems more like the result I was expecting judging from my previous test.
You will get different readings wherever you use this type of calculator. I don't think any give a 100% accuracy, they are just a guide, an indication. The accurate readings would be from a proper Blood Test. That's what you should rely on.......
Many have used these converters and been pleasantly surprised or disappointed......such is life !
if you have an iPhone/ iPad / iPod Touch then you might want to look at the thread discussing apps for them. There is at least one there which will do what you want.