Wallpaper Calculator
Enter your room's perimeter and wall height to estimate the number of wallpaper rolls needed, accounting for roll coverage and pattern repeat waste.
Results
- Rolls needed
- 9 rolls
- Wall area
- 410 sq ft
- Usable per roll
- 50.4 sq ft
Estimates only. Round up and buy a little extra to account for waste, spills, and breakage.
Wallpaper is sold by the roll but hung by the strip, and pattern repeats eat into every roll. This wallpaper calculator accounts for your room perimeter, wall height, openings, roll coverage, and repeat waste so you order the right number of rolls the first time.
Always check the roll label: American double rolls cover about 56 sq ft, while many European rolls are closer to 56 sq ft per double roll but sold as singles of 28.
Also used as a wallpaper roll calculator and wall covering estimator.
How to use the wallpaper calculator
- Enter the room perimeter in ft.
- Enter the wall height in ft.
- Enter the openings to subtract in sq ft.
- Enter the coverage per roll in sq ft.
- Enter the pattern repeat.
- Optionally add a price to estimate the total project cost.
- Read your quantities instantly — no sign-up, and you can print the estimate to take to the supplier.
Worked example
Inputs
- Room perimeter
- 50 ft
- Wall height
- 9 ft
- Openings to subtract
- 40 sq ft
- Coverage per roll
- 56 sq ft
- Pattern repeat
- Small repeat (10% waste)
Results
- Rolls needed
- 9 rolls
- Wall area
- 410 sq ft
- Usable per roll
- 50.4 sq ft
Using the example values above, the wallpaper calculator returns 9 rolls (rolls needed). Change any field to match your own project and the numbers update instantly.
How many rolls of wallpaper do I need?
Multiply the room perimeter by the wall height, subtract doors and windows, then divide by the usable coverage per roll. A room with a 50 ft perimeter and 9 ft walls has 450 sq ft, minus 40 sq ft of openings is 410 sq ft, which takes about 8 double rolls before pattern waste.
Order all rolls from the same batch or lot number; colors shift visibly between print runs.
How pattern repeat changes the count
Every strip must start at the same point in the pattern, so the top of each strip is trimmed. Small repeats waste about 10%, medium repeats 15%, and large dramatic repeats up to 25% of every roll. Random-match and plain papers waste almost nothing.
Formula
Wall area = perimeter × height − openings. Rolls = area ÷ usable coverage per roll, rounded up.
Frequently asked questions
- How many rolls of wallpaper do I need?
- Calculate wall area (perimeter × height minus openings) and divide by the usable coverage per roll, adding waste for the pattern repeat.
- Why does pattern repeat increase rolls?
- Matching a repeating pattern means trimming the top of each strip, wasting 10–25% of every roll depending on the repeat size.
- How much wallpaper for a 12x12 room?
- A 48 ft perimeter at 8 ft ceilings is 384 sq ft; minus openings you will need about 7 to 8 double rolls, or 9 to 10 with a large pattern repeat.
- Can I return unused rolls?
- Most retailers accept unopened rolls within 30 days, which is another reason to round up rather than risk a mid-job shortage.
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