Quote Originally Posted by ChrisW67 View Post
The size specified to QFont is a point size and does not directly translate to a width. The width it does give may be fractional pixels which are rounded to 10 in QFontMetrics::width(). There could be a difference over multiple characters caused summing then rounding: Summing pixel widths of 9.63 will give you figures like the ones you posted.
Yes you're right, but it is surprising the behabiour has changed since 4.7, so maybe Qt was doing the rounding before adding before?

Is there any posibility of setting the width to an integer number of pixels? (I know we don't set the width directly, but maybe there is a trick, as I think you can set the size in pixels rather than points).