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How many rolls of wallpaper do I need?
Wallpaper is hung in vertical strips (called “drops”). To work out how many rolls to buy, you find how many drops it takes to cover the wall’s width, how many drops you can cut from one roll, and divide. A pattern repeat adds waste, because each drop has to be trimmed to line the design up with its neighbour. This calculator handles all of that — measure the total width of wall you’re covering and its height, add your roll’s size, and it tells you how many rolls to order.
Always round up and buy one extra roll from the same batch (dye lots vary between batches). A US “double roll” is typically about 20.5 in wide and 33 ft long — check your roll’s label and adjust the fields.
Frequently Asked Questions
What is a pattern repeat?
It’s the vertical distance before the design starts over. To match the pattern across strips you trim some off each drop, so a larger repeat means more waste and more rolls. Enter 0 for a plain or random-match paper.
Do I subtract doors and windows?
Not usually — the offcuts above and below openings rarely yield a full usable drop, and keeping the extra protects against mistakes and mismatched batches. This calculator sizes for full coverage on purpose.
What’s the difference between a single and double roll?
A double roll is simply two singles’ worth on one roll, so you get more usable drops with fewer seams. Enter whichever roll length is printed on the packaging you’re buying.
Why buy from the same batch?
Colours can differ slightly between production batches (dye lots). Ordering all your rolls together — plus a spare — keeps the whole wall consistent.