Wallpaper Calculator
Estimate how many wallpaper rolls a room needs.
The right number of rolls
Wallpaper is bought by the roll, but coverage is reduced by trimming and pattern matching, so a naive area calculation falls short. This tool accounts for that and rounds up sensibly.
Enter the room perimeter, wall height, and usable coverage per roll, and it estimates the rolls needed with a waste allowance. A 40-foot perimeter room with 9-foot walls needs about 16 rolls at 25 usable square feet each.
Useful and private
The calculation runs in your browser, so nothing you enter is uploaded.
Frequently Asked Questions
How many rolls will I need?
It divides the wall area by the usable area per roll and rounds up, after adding a waste allowance for pattern matching.
What roll size is assumed?
A standard roll covering about 25 usable square feet after trimming and pattern repeat. Check your roll’s label and adjust.
Should I buy extra?
Yes. Buy from the same batch and keep a spare roll for repairs, since dye lots vary.
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