Snapping items to design grids
You can make items snap to master page grid lines, and when you resize a text box, you can snap to the text box grid.
To snap to a master page grid line, display the master page grid (View > Page Grid) and then choose View > Snap to Page Grid.
Note: The Snap Distance field in the Guides & Grids pane of the Preferences dialog box enables you to change the 6-pixel default distance at which items snap to page grids when Snap to Page Grids is chosen (View menu).
To snap to a text box grid line when you resize a text box, display the text box grid and resize the box.
Parent topic: Using design grids