Wallpaper Calculator

A 12x12 room with 8-foot ceilings has about 48 feet of wall. In standard American double rolls (27 inches × 27 feet) with no pattern repeat, that takes 22 strips at 3 strips per roll: 8 double rolls. A 20-inch pattern repeat typically pushes it to 11, because each roll then yields only 2 usable strips.

American wallpaper is priced by the single roll but almost always ships as double rolls: one continuous bolt twice as long (27 inches × 27 feet, about 61 square feet). If a quote says 8 single rolls, you will receive 4 double-roll bolts. Always confirm which unit a price refers to before comparing.

For patterned paper, no. The strips above and around openings usually must be cut from full-length drops to keep the repeat aligned, so the "saved" paper is rarely usable. Installers only deduct for very large openings such as a wall of glass or double doors, and for plain unmatched papers.

Every strip must be cut at the same point in the pattern, so each cut length rounds up to a full repeat. On a 9-foot wall, a 25-inch repeat turns a 112-inch strip into a 125-inch strip, often dropping a roll from 3 usable strips to 2, which adds 30-50% to the order. Half-drop matches consume slightly more again.

Order at least one extra roll from the same batch or dye lot. Batches vary visibly in color, replacement rolls from a new batch rarely match, and you will want attic stock for repairs. For grasscloth and hand-printed papers, designers often add 15-20%.