🧻 Wallpaper Calculator
Enter your room’s perimeter and height and the roll dimensions, and get how many rolls of wallpaper to buy — allowing for the pattern repeat.
Rolls to buy
7
+ a spare from the same batch
Strips (drops) needed
27
perimeter 14 m
Drops per roll
4
Rolls = drops needed (perimeter ÷ roll width) ÷ drops per roll (roll length ÷ (height + trim + repeat)). 🔒 In your browser.
How the wallpaper calculator works
The tool works out how many full drops (strips from ceiling to floor) each roll yields, given the wall height plus an allowance for trimming and pattern matching, then how many drops the room needs (perimeter ÷ roll width). Dividing one by the other, and rounding up, gives the number of rolls. A larger pattern repeat wastes more and needs more rolls.
A standard roll is about 10 m long and 0.53 m wide. Pattern repeats — especially large or “drop match” ones — increase waste because each strip must be aligned, so always round up and buy a spare roll from the same batch.
Frequently asked questions
How many rolls of wallpaper do I need?
Find how many full-height strips one roll gives (roll length ÷ (wall height + trim + pattern repeat)), then how many strips the room needs (wall perimeter ÷ roll width), and divide. Round up and add a spare roll.
What is a pattern repeat?
The vertical distance before the design repeats. To line up adjacent strips you must waste up to one repeat per drop, so large repeats mean more rolls. A “free match” or plain paper wastes the least.
What size is a standard wallpaper roll?
Commonly about 10 metres long and 0.53 metres wide (a “Euro roll”), covering roughly 5 m². American rolls differ, so enter your roll’s actual dimensions.
Should I include doors and windows?
Using the full perimeter without subtracting openings gives a safe estimate and accounts for waste and matching. For large openings you can reduce the count slightly, but it’s safer to over-order.
Why buy from the same batch?
Wallpaper colour can vary between print batches. Buy all your rolls (plus a spare) with the same batch number so they match on the wall.