Wallpaper Calculator

Calculate wallpaper rolls needed for any room with pattern repeat adjustment.

Wall Area to Cover (sq ft)
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Strips per Roll
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Rolls Needed (incl. 10% waste)
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How the Wallpaper Calculator Works

This wallpaper calculator estimates the number of rolls needed by computing the total wall area and dividing it into strips. Wall area is the room perimeter multiplied by ceiling height, minus 21 sq ft per door and 15 sq ft per window. Each roll is cut into vertical strips; the number of strips per roll depends on the roll length divided by the strip length. When a pattern repeat is set, the effective strip length increases — each strip must start at the same point in the pattern, meaning some of the roll is wasted to match. Strip count across the room is the perimeter divided by the strip width (roll width in feet). Rolls needed equals strips needed divided by strips per roll, with 10% added for waste and rounding up.

Frequently Asked Questions

How many rolls of wallpaper do I need for a 12×12 room?
A 12×12 room with 8-ft ceilings (approx. 300 sq ft of walls, minus openings) typically needs 8–10 rolls of standard US wallpaper.
How do I account for pattern repeat in wallpaper?
Add the pattern repeat to the wall height when calculating strips per roll. A 12-inch repeat on an 8-ft wall means cutting 9-ft strips, wasting some of each roll.
What is standard wallpaper roll size in the US?
US single rolls are typically 20.5 inches wide and 16.5 ft long, sold in double-roll bolts (33 ft).
Should I add extra wallpaper for waste?
Always order 10–15% extra. Odd-shaped rooms, pattern repeats and cutting errors can add up quickly.

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