Wallpaper Calculator — Rolls Needed

Measure each wall's length and the room's height in feet. Multiply to get sq ft per wall, then add them up. Subtract standard openings (15 sq ft per window, 21 sq ft per door). Divide by the usable sq ft per roll — which is roll dimensions minus pattern repeat waste — and round up. Add one extra roll for mistakes and future repairs.

Pattern repeat is the vertical distance over which a wallpaper's design repeats itself. A 10-inch repeat means the pattern restarts every 10 inches up the wall. When hanging, each new strip must align with the previous strip's pattern — which can waste up to a full repeat per strip. Larger repeats mean more waste; random (no-repeat) patterns waste almost nothing.

American wallpaper is priced and sold mostly as 'single rolls' that are actually packaged as 'double rolls' — one continuous bolt covering twice the area. A single roll covers about 30 sq ft of usable area; a double roll covers about 60 sq ft. Always confirm by sq ft, not by 'roll', since manufacturers vary.

At least one extra roll — for mistakes during install and for repairs in 5–10 years (manufacturers discontinue patterns regularly). For complex rooms with many openings, very large patterns, or contrasting accent walls, buy 15–20% extra rather than just +1.

Peel-and-stick is easier for DIYers, fully removable without damage, and ideal for renters or short-term decor. Traditional pasted wallpaper is more durable, hides wall imperfections better, and offers more pattern and texture options — but takes more skill to install and remove. For high-traffic areas like hallways and kitchens, traditional outperforms peel-and-stick on durability.