Start by measuring your available space—aim for a desk 100 to 120 centimetres...

https://astro-wiki.win/index.php/How_to_Decide_Between_a_Wider_Desk_or_Vertical_Shelves_for_Your_Workspace

Start by measuring your available space—aim for a desk 100 to 120 centimetres wide to fit your gear comfortably. Use a monitor arm to free up desk surface and create more room for your keyboard and mouse