Wallpaper Calculator
How many wallpaper rolls you need, based on perimeter, height, and pattern repeat.
Every calculation runs locally in your browser. Subtract large openings (like a wide doorway) from the perimeter first if they take up a full strip width or more.
Rolls to buy
8
Strips needed
31
Strips per roll
4
For informational and educational purposes only — not professional advice, and not a substitute for consulting a qualified professional about your specific situation. TrueMeasureKit is not liable for decisions made based on these results. See our Terms of Service.
Why wallpaper is measured in strips, not area
Unlike paint, a roll of wallpaper gets cut into full-height vertical strips — you can't spread the leftover from a short wall onto a different one, so the calculation works in whole strips rather than raw square meters. A pattern repeat adds waste because each new strip has to be shifted to line its pattern up with the one before it, effectively shortening how much usable length comes out of every roll. A roll only yields whole strips, never a fraction, which is why both numbers here round in the direction that avoids coming up short.
Frequently asked questions
Why does pattern repeat matter for how many rolls I need?
A pattern with a large repeat distance means more of each roll is lost matching the pattern across seams — two wallpapers covering the identical wall area can need a different number of rolls purely based on repeat size.