How can we calculate grades online?

What kind of "grade" are you talking about? School grades? Give us the link to this calculator, so we can take a look at it.

Using this website is very simple, (but I'm not sure why you needed to create an account just for this question...)

All you have to do is type in how many questions were on the quiz/test, and voila! magic pops up. You try, and you will see what I mean.