How to Calculate Wallpaper Rolls

Wallpaper quantity depends mainly on wall dimensions, wallpaper roll width, roll length and pattern repeat. The calculator determines the number of wallpaper drops required for each wall and estimates how many complete drops can be obtained from each roll.

Doors and windows are included in the calculation as opening areas, while the required drop count is retained to avoid underestimating wallpaper requirements.

Wallpaper Roll Calculation

Wallpaper drops are calculated by dividing the wall width by the wallpaper roll width and rounding up to the next complete drop. The required drop length is adjusted for the pattern repeat where applicable. The total number of rolls is then calculated from the number of usable drops available from each roll.

Wallpaper Calculator FAQs

How many wallpaper rolls do I need?

The number of wallpaper rolls depends on wall dimensions, roll width, roll length and pattern repeat. Larger walls or rooms with more walls generally require more wallpaper.

Does the calculator account for doors and windows?

Yes. Door and window dimensions can be entered for each wall. Their areas are reported separately, but the calculator does not automatically subtract them from the required wallpaper drops.

Does wallpaper pattern repeat affect the number of rolls?

Yes. A larger pattern repeat can increase the amount of wallpaper required because each drop may need to be cut longer to maintain pattern alignment.

Can I calculate wallpaper for multiple walls?

Yes. The calculator supports one to four walls and allows different dimensions and openings to be entered for each wall.

Should I buy extra wallpaper?

It is generally sensible to allow for installation waste, pattern matching, trimming and future repairs. The amount required depends on the wallpaper and installation conditions.