Wallpaper Calculator
Enter your walls and roll size and get the exact roll count you need, pattern repeat waste included.
Roll Specs
About this tool
What this tool does
Enter your wall dimensions and your wallpaper roll's specs, and this tool tells you exactly how many rolls to buy — factoring in the pattern repeat, which is the part most people underestimate. A large pattern repeat can waste 25% or more of every roll, because each cut strip needs to be long enough to line up with the strip next to it.
Who it's for
Anyone about to order wallpaper for a room and trying to avoid the two classic mistakes: buying too little and getting stuck mid-project with a discontinued print, or buying way too much and eating the cost of unused rolls.
How to use it
- Enter your wall height (floor to ceiling) and add a width for each wall or wall section you're covering.
- Pick a roll preset (European, UK, or US standard sizes) or enter your own roll width and length from the label.
- Enter the pattern repeat in centimeters — it's printed on the wallpaper's packaging or spec sheet; leave it at 0 for a plain, non-repeating design.
- Adjust the waste buffer if you want extra margin for mistakes (10% is a reasonable default), and optionally enter a price per roll to see an estimated total cost.
Real-world uses
Ordering the right number of rolls before a renovation, comparing how much a large-repeat designer print will cost in wasted material versus a smaller-repeat or plain option, or double-checking a quote from a decorator.
Frequently asked questions
Why does pattern repeat matter so much?
Every strip has to be cut long enough that its pattern lines up with the strip beside it. A wallpaper with a 30cm repeat wastes far more per strip than one with a 10cm repeat or no repeat at all, because each cut has to round up to the next full repeat length.
Should I subtract doors and windows from the wall area?
Usually not, for a standard room. The offcuts above and below a door or window rarely produce a usable full-height strip for another wall, so the "savings" gets eaten up by pattern-matching waste anyway. Most professional installers just measure full wall widths and don't bother deducting openings.
What's a safe waste buffer to use?
10% is the commonly recommended minimum for any wallcovering project, covering measuring mistakes and cutting errors. For a complicated room with lots of corners, alcoves, or a very large pattern repeat, bumping it up to 15-20% is safer.
What's the difference between the roll presets?
They reflect real manufacturing standards: European rolls are typically 53cm wide by 10m long, UK rolls are slightly narrower at 52cm, and US "single rolls" (often sold in double-roll bolts) run about 68.5cm by 8.2m. Always check your specific product's actual label, since some specialty papers don't follow these standards.
Can I use this for more than one room?
Calculate one room at a time by adding each of that room's walls, note the roll count, then clear the wall list (or refresh the page) and repeat for the next room.