Wallpaper Calculator
Enter your room size, doors, and windows to find the wall area and exactly how many rolls of wallpaper to buy — with extra added for pattern repeat.
A double roll is typically ~56 ft².
Leave at 0 for a solid or random match. Larger repeats waste more.
How to Calculate Wallpaper Rolls
First find your wall area: add the four wall widths together (2 × (length + width)) and multiply by the ceiling height. Subtract roughly 21 ft² for each door and 15 ft² for each window so you don't over-buy. Divide that area by the coverage of one roll — a standard double roll covers about 56 ft² — and round up to whole rolls.
Always add extra for waste. A solid or random-match paper needs about 5%, while a patterned paper needs 10–20% depending on the size of the pattern repeat, because every strip has to be aligned to its neighbor. This calculator applies that waste automatically and also shows the single-roll equivalent, since wallpaper is often priced by the single roll but sold in double-roll bolts.
Frequently Asked Questions
How many rolls of wallpaper do I need?
Calculate your total wall area, subtract openings for doors and windows, add a waste factor, then divide by the coverage of one roll and round up. A standard double roll covers around 56 square feet. Enter your numbers above for an instant count.
How do I measure a room for wallpaper?
Measure the length and width of the room and the ceiling height in feet. The wall area is 2 × (length + width) × height. Then count the doors and windows so their areas can be subtracted from the total.
Does pattern repeat affect how much wallpaper to buy?
Yes. Patterned wallpaper must be matched strip to strip, which wastes paper at the top of each drop. Add about 10% for a small repeat and 15–20% for a large repeat (12 inches or more). Solid papers only need around 5% extra.
Turn Your Measurements Into a Real Floor Plan
Once you know your dimensions, generate a labeled, to-scale floor plan in seconds — then export it to DXF or build it in 3D. No CAD experience needed.
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