Grid Settings... (Display Menu)
 
The Grid Settings command allows you to set up the scale of the grid. When you choose this menu command, a dialog box will open. The default setting for the grid is one square per square inch (English) or one square per 2.54 cm (metric). You may change the scale by typing in new numbers. For example, if you prefer to see a 1/2" grid, you will type in .5".