Wallpaper Calculator
Enter the room size, roll size and pattern repeat to calculate how many wallpaper rolls to buy — including the length trimmed off every strip to keep the pattern lined up.
Unit
Room dimensions (feet)
Leave the repeat at 0 for a plain or random-match paper. The repeat is printed on the roll label — it is the distance before the motif starts again.
Buy every roll from the same batch number, and buy the spare now rather than later — dye lots shift between print runs and a replacement roll ordered next month rarely matches the wall. A large pattern repeat is what pushes the count up: each strip is cut to the next whole repeat so the motif lines up across the seam.
Frequently asked questions
How many rolls of wallpaper do I need?
Work out how many full-width strips it takes to go round the room, then how many of those strips you can cut from one roll. Divide the first number by the second. A standard US double roll gives three 9 ft strips, so a room needing 15 strips takes 5 rolls.
What is a pattern repeat and why does it matter?
The repeat is the distance before the motif starts again, printed on the roll label. Each strip has to be cut to the next whole repeat so the pattern lines up across the seam, so a large repeat can waste a foot or more per strip and push you into buying another roll.
What is the difference between a single and a double roll?
A double roll is one continuous bolt containing twice the length of a single, usually 20.5 inches wide by 33 feet. American wallpaper is priced per single roll but almost always sold as doubles, which is why the number on the price tag rarely matches what arrives.
Should I subtract doors and windows?
Only roughly. This calculator removes about one strip width per opening, which is close for a standard door or window. Do not deduct the full area — the paper above and below an opening still comes off a full-length strip.
Why does everyone say to buy an extra roll?
Dye lots shift between print runs, so a roll ordered later can be visibly different on the wall. Buy the spare with the original order, check that every roll carries the same batch number, and keep the offcut for repairs.
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Related AI features
Not sure about the pattern? See it on your own walls before you order.
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