This wallpaper calculator estimates how many rolls to buy for the total wall width you plan to cover. It uses the wall height, roll width and length, pattern repeat and the number of doors and windows entered.
It is designed for planning a feature wall or a room before ordering. Alongside the number of rolls, it shows the adjusted wall width, strip length, number of strips, full strips per roll and effective usable length per roll.
Wallpaper Calculator
Estimate how many rolls you need, allowing for pattern matching, trimming, doors and windows.
Your Result
Wall width after doors/windows
Length per strip (incl. 4 in trim & pattern match)
Strips needed
Full strips per roll
Effective usable length per roll
Rolls to buy
Doors and windows are allowed at 3 ft of wall width each. If a door or window sits mid-wall, you may still need offcuts above and below it — consider one spare roll for patterned paper.
How to Use This Tool
- Enter the total wall width to cover and the wall height in feet.
- Add the wallpaper roll width in inches and roll length in feet.
- Enter the pattern repeat in inches, or leave it as 0 for plain wallpaper.
- Add the number of doors and windows, each allowed as 3 feet of wall width.
- Select Calculate Rolls Needed and use the rolls-to-buy figure when planning your order.
The estimate includes the calculator's allowance for trimming and pattern matching. Doors or windows in the middle of a wall can still require offcuts above and below them, and patterned paper may justify a spare roll; check the wallpaper manufacturer's guidance before ordering.
Painting as well? Work out how much paint you need with the Paint Calculator and browse our free online tools for the rest of the room.