Primary material
10 double rolls
Wallpaper (double rolls)
Use the double-roll count as a buying starting point, then confirm the roll size, pattern repeat, and dye lot — order all rolls in one batch to match lots.
Wallpaper calculator
Wallpaper calculator: how many rolls do I need?
Enter the room size, wall height, and pattern repeat to estimate wall area, full-height strips, double rolls, the single-roll equivalent, and material cost.
12 x 12 room, 8 ft walls
10 double rolls
20 single-roll equivalent
Method
Strips, not area
accounts for pattern repeat
Best for
Feature walls
and whole rooms
Quick reference
Wallpaper rolls for common room sizes
All four walls at 8 ft high using US double rolls (20.5 in x 33 ft) with no pattern repeat. A large repeat lowers the strips per roll; enter yours in the calculator.
| Room size | Wall area | Strips | Strips per roll | Double rolls | Single rolls |
|---|---|---|---|---|---|
| 10 x 10 ft | 320 sq ft | 24 | 3 | 8 | 16 |
| 12 x 12 ft | 384 sq ft | 29 | 3 | 10 | 20 |
| 12 x 15 ft | 432 sq ft | 32 | 3 | 11 | 22 |
| 15 x 20 ft | 560 sq ft | 41 | 3 | 14 | 28 |
Each strip is cut to the wall height plus trim; a pattern repeat means fewer full strips per roll.
Quick wallpaper answers
Common room roll counts
12 x 12 room
8 ft walls, 1 door, 1 window
10 double rolls
order one batch to match the dye lot
10 x 14 room
8 ft walls, 1 door, 1 window
10 double rolls
order one batch to match the dye lot
12 x 16 room
9 ft walls, 1 door, 2 windows
11 double rolls
order one batch to match the dye lot
Feature wall
Papering one wall? Set the room length and width so the perimeter equals just that wall's width, and the calculator counts strips for the accent wall only.
Shopping list
Wallpaper, paste, and tools
Adhesive
Paste or activator
Unpasted paper needs wallpaper paste; prepasted needs water or an activator; peel-and-stick needs neither. Match the adhesive to the paper.
Wall prep
Primer and sizing
A wallpaper primer/sizing helps paper stick and makes future removal easier. Patch and sand the wall smooth first.
Install tools
Smoother, seam roller, and knife
Hanging paper needs a smoothing brush or plastic smoother, a seam roller, a sharp snap-blade knife, a level, and a table or trough.
Formula shown
How the wallpaper calculation works
1. Perimeter and wall area
perimeter = 2 x (length + width); wall area = perimeter x height
2. Number of strips (drops)
drops = ceil(perimeter / roll width)
3. Strips per roll with repeat
strip length = height + trim, rounded up to a whole pattern repeat; strips per roll = floor(roll length / strip length)
4. Rolls needed
double rolls = ceil(drops / strips per roll)
Why rolls beat a raw area estimate
A double roll holds about 56 sq ft, but with 8 ft walls you only get whole strips out of it and the leftover length is wasted. Counting strips captures that cutting waste, so it is more reliable than dividing wall area by roll coverage.
Sources
- Wallpaper Boulevard roll coverage — square feet per single and double roll, usable yield after trim
- US Wall Decor single vs double roll — US single roll 20.5 in x 16.5 ft, double roll 33 ft conventions
- Sherwin-Williams wallpaper guidance — pattern repeat, strip cutting, and dye-lot ordering context
Sources checked
Checked against
Coverage rates checked against paint manufacturer and retailer calculator guidance.
How we check our numbersLast updated: July 3, 2026
Estimate only.
This calculator is not a quote. Verify product yield, price, delivery minimums, and local conditions with your supplier or contractor before buying materials.
FAQ
Wallpaper calculator questions
Answers for wallpaper roll counts, double vs single rolls, pattern repeat waste, and openings.
How many rolls of wallpaper do I need? + -
Measure the room perimeter and wall height. The number of full-height strips (drops) is the perimeter divided by the roll width, and the strips you get from one roll is the roll length divided by the strip height plus trim. Rolls needed is the total drops divided by strips per roll, rounded up. This calculator does all three steps.
What is a double roll of wallpaper? + -
In the United States, wallpaper is priced by the single roll (about 20.5 in wide by 16.5 ft, roughly 28 sq ft) but packaged and sold as double rolls (one continuous 33 ft length, about 56 sq ft) so you get more full strips with less waste. This calculator counts double rolls and also shows the single-roll equivalent.
How does the pattern repeat change how much wallpaper I need? + -
A pattern repeat forces each strip to be cut to a whole number of repeats so the pattern lines up across seams. The offcut above each repeat is wasted, so a larger repeat means fewer usable strips per roll and more rolls. Enter the repeat from the roll label to account for it.
Should I subtract doors and windows? + -
This calculator leaves small doors and windows in as safety margin, which matches common trade advice, and shows the net wall area after openings so you can judge. For very large openings, a full wall of glass, or an accent wall, you can subtract a roll or two.
Is this wallpaper estimate exact? + -
No. It is an estimate for planning and buying. Confirm the exact roll width, length, and pattern repeat on the product label, order all rolls in the same batch to match dye lots, and keep a spare roll for repairs.