Wallpaper Calculator – How Many Rolls Do I Need?
Our free wallpaper calculator tells you how many rolls of wallpaper you need for a room or a single accent wall. Enter the room size and wall height, pick your roll size, and add the pattern repeat and match type from the label. The calculator counts real strips instead of guessing from square feet, handles doors and windows, and shows the rolls to buy, the strips per roll, the cost, and a printable list.
How to Use the Wallpaper Calculator
- Choose room or wall. “Whole room” takes the length and width and papers all four walls. “Single wall” is for an accent wall or a stairwell section.
- Enter the wall height. Measure from the floor or the top of the baseboard to the ceiling or crown molding, in several places, and use the largest number.
- Count doors and windows. Enter how many there are. The default sizes are 36 × 80 inches for a door and 36 × 48 inches for a window, and you can change them.
- Pick the roll. Choose a US double roll, a US single roll, a Euro roll, a wide roll, or enter your own width and length from the label.
- Add the pattern. Select the match type (free, straight, or half-drop) and type the pattern repeat from the label, for example 21 inches.
- Check the extras. Each strip gets a trim allowance of 4 inches by default, 2 at the top and 2 at the bottom. Check “Add one spare roll” if you want a reserve for repairs.
- Copy or print. The list with rolls, strips, sizes, and settings goes to your clipboard or prints on US Letter or A4.
Why We Count Strips Instead of Square Feet
The simple method divides the wall area by the area of a roll. It looks precise, but it often comes up short. A US double roll is 20.5 inches wide and 33 feet long, about 56 square feet. You can never use all of it, because each roll is cut into strips of one wall height, and the rest of the roll is often too short for another full strip.
So the calculator works like a paperhanger does:
- Strip length = wall height + trim allowance, rounded up to whole pattern repeats
- Strips per roll = roll length ÷ strip length, rounded down
- Strips needed = wall width (or room perimeter) ÷ roll width, rounded up
- Rolls = strips needed ÷ strips per roll, rounded up
The short pieces above doors and above and below windows are then fitted into the leftovers of the rolls. Only if they do not fit does the calculator add another roll.
Example: a 12 × 12 Bedroom
The room has 8 ft walls, one door, and two windows, and you use a US double roll without a pattern repeat. Each strip is 96 + 4 = 100 inches long, so a 396 inch roll gives 3 strips. The perimeter of 48 ft is 576 inches, which needs 29 strips of 20.5 inches. The door and each window replace one full strip, so 26 full strips remain, and that is 9 rolls. The three short pieces over the door and around the windows fit into the leftovers of those rolls, so the answer stays at 9 rolls.
The simple area method would say 340 sq ft ÷ 56 sq ft = about 6 rolls, which would leave you several strips short.
Example: an Accent Wall With a Pattern
A wall 14 ft wide and 9 ft high gets a paper with a 21 inch straight-match repeat. The wall height plus trim is 112 inches, rounded up to 6 repeats, which makes 126 inch strips. A double roll gives 3 of them. The wall needs 9 strips, so you buy 3 rolls. With a half-drop match, each strip needs half a repeat more (136.5 inches), a roll gives only 2 strips, and you need 5 rolls.
Wallpaper Roll Sizes
Roll sizes are not the same everywhere. Always check the label, which gives the width, the length, and often the coverage.
| Roll type | Width × length | Total area |
|---|---|---|
| US double roll | 20.5 in × 33 ft | about 56 sq ft |
| US single roll | 20.5 in × 16.5 ft | about 28 sq ft |
| Euro roll | 0.53 × 10.05 m (about 21 in × 33 ft) | about 5.3 m² (57 sq ft) |
| Wide roll | 0.70 × 10.05 m (about 27.5 in × 33 ft) | about 7 m² (76 sq ft) |
In the US, wallpaper is often priced per single roll but sold only in double rolls. Read the price carefully, and if you are unsure, use “Custom size” with the width and length from the label.
How Much Wall Does One Roll Cover?
This is the question most people search for, and the honest answer is “It depends on the wall height.” The table shows the usable wall area of one US double roll (20.5 in × 33 ft) with a 4 inch trim allowance:
| Wall height | No repeat | 21 in straight match | 24 in half-drop |
|---|---|---|---|
| 8 ft | 3 strips, 41 sq ft | 3 strips, 41 sq ft | 3 strips, 41 sq ft |
| 9 ft | 3 strips, 46 sq ft | 3 strips, 46 sq ft | 3 strips, 46 sq ft |
| 10 ft | 3 strips, 51 sq ft | 3 strips, 51 sq ft | 2 strips, 34 sq ft |
| 12 ft | 2 strips, 41 sq ft | 2 strips, 41 sq ft | 2 strips, 41 sq ft |
A double roll of 56 sq ft rarely covers more than 41 to 51 sq ft of wall, and sometimes much less. Many wallpaper makers give a rule of thumb of 45 to 50 square feet per double roll. Treat that as a guide value and let the strip count decide.
Pattern Repeat and Match Types
The label shows the vertical pattern repeat (the distance until the design starts again) and a match symbol:
- Free match (random): stripes, textures, and grasscloth that line up anywhere. No repeat to add, and the least waste.
- Straight match: the design lines up straight across from strip to strip. Each strip is rounded up to whole repeats.
- Half-drop match: every second strip is shifted down by half a repeat. This needs the most paper, and the calculator adds half a repeat to every strip.
A large repeat on a wall that is just a little taller than a whole number of repeats wastes the most. If you can choose between two papers you like, compare them in the calculator before you buy.
Doors, Windows, and Other Openings
A door 36 inches wide is wider than one strip of 20.5 inches, so it replaces one full strip. Above the door you still need a short piece. Windows need short pieces above and below. The calculator removes only the full strips that an opening replaces and cuts the short pieces from leftovers, which is how most installers work.
Narrow openings smaller than one roll width do not replace any strip, so they save no paper. If you uncheck “Subtract doors and windows,” the calculator counts all walls as solid, which gives you a small reserve.
Before You Hang the Paper
- Remove the old paper first. Our guide on how to remove wallpaper covers steamers, scoring tools, and stubborn glue.
- Repair and prime the walls. Fill holes as shown in how to fill screw holes in a wall, sand smooth (see how to sand drywall), and seal new drywall with a primer from our guide to the best drywall primer.
- Know your walls. Plaster and drywall take paper differently. Read plaster vs. drywall if you live in an older home.
- Measure the height properly. Our article on standard ceiling height explains how to measure, and why one corner can differ from another.
- Buy one batch. All rolls should have the same batch (lot) number, because colors can vary slightly between print runs.
Would you rather paint than paper? Our guide to limewash walls shows a textured finish that also hides small flaws.
Metric Units and Privacy
Switch to metric to enter meters and centimeters. The Euro roll of 0.53 × 10.05 m is then the standard, with a trim allowance of 10 cm. The calculator runs in your browser, needs no sign-up, and nothing you enter is sent anywhere. All results are estimates. The label of your wallpaper and the advice of the maker come first, especially for murals and panels that come in numbered sets.
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Frequently Asked Questions
How Many Rolls of Wallpaper Do I Need?
Work out how many strips fit across your walls (width ÷ roll width) and how many strips one roll gives (roll length ÷ strip length). Divide the first by the second and round up. A 12 × 12 ft room with 8 ft walls usually needs about 9 US double rolls without a large repeat.
How Much Does a Double Roll of Wallpaper Cover?
A US double roll has about 56 square feet, but after trimming and pattern matching it covers about 41 to 51 square feet of wall, depending on the wall height and the repeat.
How Many Rolls of Wallpaper for an Accent Wall?
A 12 ft wide wall that is 8 ft high needs 8 strips. With 3 strips per double roll, you need 3 rolls. A large repeat or a half-drop match can raise that.
What Is a Pattern Repeat on Wallpaper?
It is the vertical distance after which the design repeats. Each strip has to start at the same point of the pattern, so strips are cut in whole repeats, which adds waste.
Do I Subtract Doors and Windows for Wallpaper?
Only openings wider than one roll save a full strip. You still need short pieces above doors and above and below windows, which usually come from leftovers.
How Much Extra Wallpaper Should I Buy?
With a strip count, you already include trimming and pattern waste. Many people add one spare roll from the same batch for repairs, especially with a patterned paper.
What Is the Difference Between a Single Roll and a Double Roll?
A US double roll is twice as long as a single roll (33 ft instead of 16.5 ft). Longer rolls waste less paper, because there are fewer short leftovers.
Is the Wallpaper Calculator Free?
Yes. It is free, needs no account, works in imperial or metric units, and lets you copy or print the results.
Robert Thompson has worked as a self-employed carpenter for over 15 years. He lives with his family in Billings, Montana, where he also successfully operates his business as a woodworker. His main business is the complete interior construction of buildings. He is also passionate about creating high-quality wood furniture with epoxy and other items made from burl wood. Besides the woodwork, Robert is also a skilled DIY professional for all kinds of materials. He always has a solution ready for every craft and construction challenge. Originally, Robert studied civil engineering and has advanced degrees in carpentry and business management. Robert has been working for Craft Art since 2020 and enriches the blog with his immense knowledge and skills in the field of woodworking and home improvement. He writes the articles about DIY and Repair.
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