Buy the right number of rolls.
Enter your room and see exactly how many rolls you need, what the job costs, and how doors, windows and the pattern repeat change the amount you have to buy.
The room
What to know before you buy
Wall area vs what you cover
Where the surface goes
Wallpaper scorecard
Rolls and cost by pattern repeat
Same wall area, four common pattern repeats, at your price per roll. The row matching your repeat is highlighted. A bigger repeat wastes more paper at the seams.
| Pattern repeat | Waste | Rolls | Cost |
|---|
Wallpaper, explained
How to Calculate Wallpaper Rolls
Calculate the room perimeter (2 x length + 2 x width). Determine how many strips each roll yields by dividing the roll length by the room height. Calculate the total strips needed by dividing the perimeter (in inches) by the roll width. Subtract strips for doors and windows. Divide total strips by strips per roll and round up. Add 10% for waste, pattern matching, and mistakes.
Wallpaper Roll Sizes and Pattern Repeats
Standard US wallpaper rolls are 20.5 inches wide and 33 feet long (about 56 sq ft). European rolls are typically 21 inches wide and 33 feet long. Double rolls provide twice the length. Pattern repeats increase waste, a large pattern repeat (24 inches or more) may require 15-20% extra material beyond the basic calculation.
Common questions
How many rolls of wallpaper do I need for a 12x15 room?
A 12x15 foot room with 8-foot ceilings has 54 feet of perimeter. Using standard 20.5-inch rolls, you need approximately 8-10 single rolls after subtracting for doors and windows and adding 10% waste. This calculator provides the exact number.
What is the difference between single and double rolls?
A single roll is typically 33 feet long and a double roll is 66 feet long. Most wallpaper is sold in double rolls but priced per single roll. Always check whether the listing price is per single or double roll.
How much extra wallpaper should I buy?
Buy 10-15% more than calculated. Pattern matching creates waste, and having extra ensures you can cover mistakes or repair damage later. Dye lots vary between production runs, so having enough from one batch is important.
Do I subtract for doors and windows?
Yes, subtract the area of doors and windows from the total wall area. Standard doors are about 21 sq ft and standard windows about 15 sq ft. However, be conservative with deductions, you still need partial strips around openings.
Estimates for planning only. Real coverage depends on the roll size, the pattern repeat, how the paper is hung and how much you trim around openings. A double roll covers roughly 56 sq ft, but usable coverage drops with the pattern match, so buy one extra roll for repairs and keep the dye lot number.