Wallpaper roll calculator
Count the rolls your room needs the way a paperhanger does: by strips, pattern repeat and match, with a spare for trimming.
Set your room size and press the button. The count includes trim allowance, pattern matching and a spare roll.
How the calculator counts
It adds up the room perimeter, takes out about 30 inches for each door and 18 inches for each window, and divides by the roll width to get the number of strips. Each strip is your wall height plus 4 inches for trimming at the ceiling and baseboard.
With a pattern repeat, every strip is rounded up to a whole repeat so the pattern lines up across the seams. A half-drop match adds half a repeat more, because every other strip starts lower on the roll. Then it works out how many full strips one roll yields and adds a spare roll for every ten, with a minimum of one.
For the detail, read how many rolls of wallpaper a room needs. For hanging, see wallpaper installation and wallpaper removal.
Calculator questions
Why does the wallpaper calculator add a spare roll?
Trimming, an occasional damaged strip and future patches all need paper from the same print batch. A spare roll from the original dye lot is far cheaper than redoing a wall when a second order does not match.
Does the roll calculator work for sloped ceilings and stairwells?
Not well. Stairwells and attic rooms have strips of very different lengths, so the count can be off by several rolls. Measure the tallest drop as your wall height for a rough number, then call us for an exact count.
Where do I find the pattern repeat for the wallpaper calculator?
It is printed on the roll label or the product page, usually in inches, with the match type next to it. Straight match, half-drop and random match each change how much paper the room uses.
Want us to measure instead?
Call any hour. We count rolls at the walk-through and can hang paper you have already bought.