Wallpaper Rolls Calculator
Estimate how many rolls of wallpaper you need from your room perimeter, wall height and roll size.
How it works
Strips per roll = roll length ÷ (wall height + trim); rolls = strips needed ÷ strips per roll
Each roll yields a whole number of full-height strips after trimming a little top and bottom. Divide the wall run by the roll width for strips needed, then by strips per roll for rolls — rounding up both times.
Worked example
A 40 ft perimeter, 9 ft walls and 33 ft rolls gives 3 strips per roll and about 8 rolls.
Frequently asked questions
Does a pattern repeat change this?
Yes — large repeats waste more per strip. Buy an extra roll for patterns over about 12 inches.
Should I round up?
Always. Order a spare roll from the same batch for repairs and to avoid color mismatch later.
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This calculator is for educational purposes. Double-check important results before acting on them.