Emacs Font is wider than other applications. Most people don't notice the difference. If you can perceive it, you are not hallucinating. This can be attributed to the following: Points per inch #ifndef HAVE_ANDROID /* Number of pt per inch (from the TeXbook). */ #define PT_PER_INCH 72.27 #else /* Android uses this value instead to compensate for different device dimensions. */ #define PT_PER_INCH 160.00 #endif Emacs definition is larger than the standard definition . The DTP point is defined as 1⁄72 of an inch. Round-off error Emacs definition : /* Return a pixel size (integer) corresponding to POINT size (double) on resolution DPI. */ #define POINT_TO_PIXEL(POINT, DPI) ((POINT) * (DPI) / PT_PER_INCH + 0.5) /* Return a point size corresponding to POINT size (integer) on resolution DPI. Note that though point size is a double, we expect it to be rounded to an int, so we add 0.5 here. If ...