Berthold Barth 22 April 2010 I’m wondering how many digits after the dot you really need. 1.667 rounds up to either 1.67 or even 1.7. At 12 pixels (which is, as I understand it, the way CSS interprets the em of a 12 px font) the errors amount to 0.04 and 0.4 pixels respectively, which in and of themselves can’t really exist. My LCD has no half-pixels. Wouldn’t it be OK to just round up and be done with the whole fractions business? Surely, if there is any kind of rounding difference between engines, rounding ourselves eliminates errors. (A late) thank you for this article.