A 48x24 desk gives you just enough space for a 27-inch monitor, keyboard, and a...

https://hotel-wiki.win/index.php/Is_a_28_Inch_Desk_Height_Too_Tall_for_Me%3F_A_Guide_to_Ergonomic_Workstation_Setup

A 48x24 desk gives you just enough space for a 27-inch monitor, keyboard, and a cup of coffee without feeling cramped