A bright attic study with snow outside the window. A large black-and-white world map desk mat covers most of a pale wooden desk, with a white keyboard and a mouse on it, a monitor behind them and a grey chair pushed in.

What Size Desk Mat Do I Need? A Step-by-Step Way to Measure

— Epic Design Pads
Pick a mat narrower than your desk that holds your keyboard with enough room beside it for the mouse. This guide walks through the measuring, with tables for every size.