Enter your room and roll size (with pattern repeat) to get the number of wallpaper rolls — waste included.
This wallpaper calculator tells you how many rolls to buy. It measures the wall perimeter (twice length plus width) and divides by the roll width to get the number of drops (vertical strips) around the room. Then it works out how many drops come from one roll — the roll length divided by the wall height plus pattern repeat — and divides to get the rolls. Patterned paper needs each drop rounded up to a whole pattern repeat so the design lines up, which uses a little more.
Always buy from the same batch number so colours match, and get one extra roll for mistakes and future repairs. This estimate treats walls as solid; large windows and doors reduce it slightly, but keeping the spare covers the difference.
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