Wallpaper Calculator
Rolls of wallpaper.
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About Wallpaper Calculator
The Wallpaper Calculator tells you exactly how many rolls to buy for a room. Enter your total wall width (or room perimeter) and height, the roll width and length, the pattern repeat, and how many doors or windows to subtract. It works out the strips you need, how many strips come from each roll, and rounds up to the rolls required while accounting for pattern-repeat waste.
It works in feet or meters and updates instantly as you type. The tool is completely free with no sign-up or limits, and it runs entirely in your browser, so nothing you enter is ever uploaded or stored.
Frequently asked questions
- How many rolls of wallpaper do I need?
- Divide the width you want to cover by the roll width and round up to get the number of full-height strips (drops). Then divide the roll length by each strip's cut length to see how many strips one roll yields, and divide the strips needed by that, rounding up. This calculator does all of that for you and adds pattern-repeat waste automatically.
- How does the pattern repeat affect how much I need?
- With a patterned paper, every strip has to be cut to the next whole multiple of the repeat so the design lines up between drops. That means a taller cut length and more waste per strip, which can reduce how many usable strips you get from each roll. Enter 0 for a plain paper with no repeat.
- Should I subtract doors and windows?
- You can. Each door or window you enter removes roughly 0.9 m (about 3 ft) of wall width from the run, since you still need short strips above and below openings. For a safe estimate on rooms with only small windows, you can leave openings at 0 and rely on the spare roll.
- Do I need extra rolls for waste?
- It's smart to buy one extra roll beyond the calculated number for trimming mistakes, matching, and future repairs. Also make sure every roll shares the same batch (lot) number, because color can vary slightly between print runs.
- Is this wallpaper calculator free?
- Yes, it is completely free to use with no account, sign-up, subscription, or usage limits. You can run as many estimates as you like.
- Is my data uploaded or stored anywhere?
- No. Every calculation runs entirely in your browser using JavaScript. Your measurements are never sent to a server, saved, or shared, so your inputs stay private on your own device.