Find out how many rolls of wallpaper you need for a wall or a whole room, how a pattern repeat affects it, and what the project might cost.
Wallpaper Installation Guidelines
Standard Roll Sizes:
- US Standard: 20.5″ wide × 16.5 feet long (≈28 sq ft)
- European: 21″ wide × 33 feet long (≈56 sq ft)
- Commercial: 27″ wide × 27 feet long (≈60 sq ft)
Pattern Repeat Guidelines:
- No pattern/random match: 5-10% waste
- Small repeat (0-6″): 10-15% waste
- Medium repeat (7-18″): 15-20% waste
- Large repeat (19″+): 20-25% waste
Important Tips:
- Always buy from the same batch/dye lot for color consistency
- Order 1-2 extra rolls for future repairs
- Subtract 15 sq ft for standard door, 10 sq ft for window
- Consider ceiling height and pattern repeat when ordering
- Pre-pasted wallpaper is easier but traditional paste offers better control
- Proper wall preparation (cleaning, priming) is essential
What this wallpaper calculator does
- Single Wall: wall width and height, roll size and waste factor to the number of rolls.
- Full Room: room length, width and height, taking off doors and windows.
- Pattern Match: uses the wall height and the pattern repeat to work out how many strips fit on a roll and how many rolls you need.
- Cost Estimator: rolls × price per roll, plus labour and supplies.
How it is calculated
Roll coverage = roll width (inches ÷ 12) × roll length in feet. The default roll is 20.5 inches wide, the standard US width, and you can also choose 21 or 27 inches. Rolls needed = area × (1 + waste %) ÷ roll coverage, rounded up. In the Full Room tab, 15 square feet is deducted for each door and 10 for each window.
For patterned paper, each strip must be as long as the wall height plus one pattern repeat. Strips per roll = roll length ÷ strip length, rounded down, and the calculator shows the extra waste this creates.
Worked examples: a 12 ft × 8 ft wall with 10% waste needs 2 rolls of 20.5 inch × 33 ft paper (56.4 sq ft each). A 12 × 10 ft room with 8 ft walls, 1 door and 2 windows has 317 sq ft to cover and needs 7 rolls. For 300 sq ft of 8 ft wall with a 16 inch repeat, each strip is 112 inches, 3 strips fit on a 33 ft roll, so you need 8 rolls and lose about 15% to matching. In the Cost tab, 300 sq ft with 10% waste at $40 per roll (56.4 sq ft each), $2 per sq ft labour and $50 of supplies is $890.
Things to keep in mind
The Single Wall and Full Room tabs use an area method, which is a good estimate for plain papers. For patterns, use the Pattern Match tab, and check the roll size and repeat printed on your paper. Buy all rolls from the same batch so the colour matches. These are planning estimates only. Measure your own project carefully, check product labels and local building codes, and confirm quantities with your supplier or a qualified contractor before you buy.
Frequently asked questions
What is a pattern repeat?
The vertical distance before the pattern starts to repeat. A larger repeat means more paper is lost when matching strips.
Why do I need extra rolls for a pattern?
Strips must line up, so part of each roll is cut off to match the pattern.
Looking for more? See all our free construction and home improvement calculators.