Size.width /= CGFontGetUnitsPerEm(cgfont) Īlthough it seems as if this is only used for estimating the size of the window, rather than the size of the font being rendered. Lines 11 - 12: ** Description: Attempts to measure font metrics because the OS's metrics Please keep in mind that it seems to occasionally ignore the font size and come up with it's own as it has a class called FontSizeEstimator which has the following in its comments You should be able to find these files with the command find / -name ist, and since the name 'Default' suggests there may be other property lists, you can find them with grep -R 'Normal Font' / or grep -R 'Non Ascii Font' / The default values both being Monaco 12, if you were to change it to Consolas 16 or Source Code Pro 16 it should do what you want. In the General category, click the Use This Font drop-down. I haven't tested this, but a brief review of iTerm's source code suggests your font preferences are stored in a property list named ist, under the keys Normal Font and Non Ascii Font. How to Change Excel 2010s Default Font and Font Size Click the File tab and then click Options.