Free tool
How many rolls will this room take?
Wall area minus openings, divided by roll coverage, rounded up. Pattern repeats can push it higher.
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Tools
From perimeter to rolls
The wall area is the room perimeter multiplied by ceiling height. Doors and windows are subtracted because they are not papered. The result is divided by the coverage of one roll and rounded up, because a partial roll cannot be bought.
This is a surface-area estimate. It does not model pattern matching, which wastes material equal to roughly one repeat per drop, and it does not model off-cuts around openings.
Buy one spare roll
Different production batches can differ slightly in colour. A spare roll from the same batch protects against a miscut or a repair years later; the same roll bought next year may not match.
Frequently asked questions
Does the calculator account for pattern repeat?
No. For a large repeat, add roughly 10 to 20 percent to the roll count, or ask the retailer to compute drops from the repeat length.
Should I subtract windows and doors?
Yes, as area. Enter their combined area in the openings field. The off-cuts around them are already covered by the waste allowance.
How much is one roll?
It varies by brand and region. Use the coverage printed on the roll, not a rule of thumb.
What ceiling height should I use?
The tallest point of the wall you are papering. A sloped ceiling needs a drop length measured at the highest point.