I really don't know as I don't use on line converters..
Whether a meter tally's up with an HbA1c will be totally dependant on two factors, how many times you test on average a day, and what happens to your blood glucose between testing..
What is your standard deviation saying?
What I actually do, is I only ever use one meter for all testing (keeping my back meter for emergency use) I then note down what my meter tells me is my average is for 90 days then when I get my HbA1c result compare the differences in that meter, if you've got a good monitoring regime, then you can work out and know what to expect.. One my pump meter now I know to expect my HbA1c to come in 0.4 below what my meter is telling me..
But with saying all that, I don't sort of take much notice of my HbA1c as such, but work with my meter and looking at the SD both overall and for individual meals aiming to keep this to a minimum as the lower the SD over all and meal to meal the better daily control you have, and the better HbA1c result you get..