The information in this article applies to:
The display of dimensions on my screen is too small when I am zoomed out. How can I make their display bigger so that they are easier to read, without affecting the size they will be when printed?
The on-screen size of dimensions and object labels can both be specified in the Preferences dialog on the Appearance panel.
This is the on-screen size and does not affect printed or exported output. To use the printed scale, set these values to 0 or turn on Print Preview.