Wallpaper Calculator

In the US, a standard single roll is 20.5 inches wide and 33 feet long (about 56 sq ft of coverage). European rolls are typically 21 inches wide and 33 feet long. Double rolls are twice the length. Always check the dimensions on the roll you plan to buy.

Pattern repeat is the distance between identical points on the wallpaper design. Patterns must be aligned across strips, which means each strip is cut longer than the wall height to allow matching. A 12-inch repeat on an 8-foot wall wastes roughly 6 inches per strip, increasing your total roll count.

Buy at least 1 extra roll beyond the calculated amount for touch-ups and mistakes. Wallpaper dye lots vary between production runs, so matching later may be impossible. With a 10% waste factor already included, 1 extra roll is usually sufficient.

Yes. Doors and windows are not papered, so subtracting their area gives a more accurate estimate. However, you still need full-width strips above windows and doors, so the actual savings may be slightly less than the raw area subtraction.

Yes. For a single accent wall, set the room dimensions so the perimeter only includes that wall. For example, enter the wall width as "length" and a very small value (0.1) as "width" so the calculation focuses on just one wall surface.