Wallpaper Calculator
Calculate how many rolls of wallpaper you need for a room, based on wall perimeter, ceiling height, roll width and roll length.
How to use the wallpaper calculator
- Enter the wall perimeter of the room — add up the length of all the walls (you don't need to subtract doors and windows, this gives a bit of extra margin).
- Enter the ceiling height.
- Enter the roll width and roll length from the wallpaper you've chosen — a standard European roll is often 53 cm wide and 10.05 m long.
How wallpaper needs are calculated
The calculator first finds how many strips (vertical pieces) are needed around the whole room, and how many strips each roll gives:
Strips per roll = Roll length ÷ Ceiling height (rounded down)
Number of rolls = Number of strips ÷ Strips per roll
"Strips per roll" is rounded down because you can only use whole strips from each roll — a roll that gives 4.18 strips in practice only gives 4 full strips.
Frequently asked questions
Should I subtract area for doors and windows?
Usually not necessary — using the full wall perimeter gives a natural safety margin for cutting, mistakes and future repairs.
What does "pattern repeat" mean on a wallpaper roll?
Pattern repeat is the distance the pattern repeats itself. Wallpaper with a repeat requires you to offset each strip for the pattern to line up, which creates more waste and therefore higher consumption than estimated here.