How Much Wallpaper Do I Need?

Start with the same net wall area used for paint — perimeter × height, minus doors and windows. Then divide by your roll's coverage: a standard US double roll covers about 56 sq ft, while European single rolls cover about 29 sq ft.

Wallpaper needs a higher waste allowance than paint — 15% is a safer default than paint's usual 10%, since every strip has to be trimmed to match the pattern at each seam. Large, bold pattern repeats need even more waste than a subtle or random texture.

The Wallpaper Calculator converts your wall dimensions directly into a roll count, with the door/window subtraction and waste built in.

A pattern repeat under 6 inches needs minimal extra waste beyond the 15% default, but a large repeat — 24 inches or more, common in bold statement wallpaper — can push effective waste past 25%, since entire extra strips sometimes have to be cut just to align one repeat correctly.