Sir, that is pretty dang close, for which I give you much credit, as I do not know how you ascertained such information. But it is not quite right. It is slightly bigger than my row heights. I know it is the case because 0.49 cm = 0.1929134 inches. I put the latter figure into the part asking me for it and if I do so for each row, my last row, the one that is not quite as large as the other ones (the one that all real index cards have too), ends up on a different page.

Therefore your estimation, though much more accurate than anything of which I am capable, is not quite on the dot. Can we get closer?

(I think they make this more difficult than it need be!)