Wallpaper Calculator
Calculate exactly how many rolls of wallpaper you need. Accounts for room size, pattern repeat, doors, windows, and different roll sizes.
Room Dimensions
Standard is 8 ft
Doors & Windows
Each 36 in door saves one strip
Each window saves one strip
Roll Width
Roll Length
Pattern Repeat
Each strip is rounded up to a full repeat so the pattern lines up
Your Results Will Appear Here
Enter your room dimensions, choose a roll size and pattern repeat, then click “Calculate” to see how many rolls you need.
Top-Rated Wallpaper & Supplies
Hand-picked products to help you get the best results on your project.
RoomMates
RoomMates Grasscloth Peel & Stick Wallpaper, Tan, 20.5" x 16.5 ft
- ✓Peel & stick
- ✓Repositionable
- ✓No paste needed
NuWallpaper
NuWallpaper Shiplap Peel & Stick Wallpaper, White/Off-White, 20.5" x 18 ft
- ✓Realistic shiplap look
- ✓Easy to apply
- ✓Removable
Hoisue
Wallpaper Smoothing Tool Kit, 7 in 1 with Squeegee, Craft Knife & Blades
- ✓7-in-1 kit
- ✓Smoothing squeegee
- ✓Cutting tools included
Zinsser
Zinsser Universal Wallcovering Adhesive, 1 Gallon
- ✓Universal adhesive
- ✓Clear drying
- ✓Easy cleanup
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How to Use This Wallpaper Calculator
Step 1: Measure Your Room
Measure the length and width of your room in feet. For an accent wall, enter only that wall’s width as the length and set the width to 0.
Step 2: Set Ceiling Height
Enter your ceiling height. Standard ceilings are 8 feet. Higher ceilings need more wallpaper per strip.
Step 3: Count Openings
Count all doors and windows. We subtract ~20 sq ft per door and ~15 sq ft per window from your total wall area.
Step 4: Choose Roll Size
Select your roll width and length. US standard is 20.5" wide × 33 ft. Check your wallpaper product for exact dimensions.
Step 5: Set Pattern Repeat
Select your pattern repeat size. Solid colors or textures have no repeat. Larger patterns waste more material during alignment.
Step 6: Get Results
Click Calculate to see the exact number of rolls, wall area breakdown, and estimated cost range for your project.
Understanding Wallpaper Rolls & Pattern Repeat
Common Roll Sizes
| Type | Width | Length | Coverage |
|---|---|---|---|
| US Single Roll | 20.5" | 16.5 ft | ~28 sq ft |
| US Double Roll | 20.5" | 33 ft | ~56 sq ft |
| Euro Standard | 21" | 33 ft | ~58 sq ft |
| Wide Roll | 27" | 33 ft | ~74 sq ft |
What Is Pattern Repeat?
Pattern repeat is the vertical distance between where the design starts repeating. When hanging strips side by side, you need to align the pattern at the same height. This means trimming some wallpaper from each strip, creating waste. The larger the repeat, the more waste you’ll have. Because paper is hung in full-height strips, the offcut at the end of every roll is also lost, which is why dividing wall area by roll area underestimates.
Single vs. Double Rolls
Most US wallpaper is sold in double rolls (bolts, about 33 ft), even though prices are often quoted per single roll (about 16.5 ft). A double roll gives you longer continuous strips, which reduces waste from ceiling-height cuts. When shopping, always check whether the listed price is per single or double roll to avoid confusion.
Pro Tips for Wallpaper Installation
Always Order 1–2 Extra Rolls
Mistakes happen, and you’ll want extras for pattern matching at corners and future repairs. Wallpaper from different production runs (dye lots) can have subtle color differences, so buy everything at once.
Check All Rolls Have the Same Batch Number
Before starting, verify that every roll has the same batch or dye lot number printed on the label. Even slight variations between batches can be noticeable once hung on the wall.
Start from the Least Visible Corner
Begin hanging wallpaper from the corner least visible when entering the room (often behind the door). The last strip you hang will likely need a pattern break—hiding it in an inconspicuous spot.
Use a Plumb Line for the First Strip
Walls are rarely perfectly straight. Use a plumb line or laser level to mark a true vertical line for your first strip. Every subsequent strip aligns to this one, so accuracy here prevents compounding errors.
Let Paste ‘Book’ for 5–10 Minutes
After applying paste, fold the wallpaper (paste to paste) and let it rest for 5–10 minutes. This ‘booking’ process allows the paper to expand evenly and the adhesive to activate, preventing bubbles and uneven stretching.
Frequently Asked Questions
A 12×12 room with 8-foot ceilings takes about 29 strips of standard 20.5-inch paper; a door and two windows save about 3. With 4 inches added for trimming, each strip is 100 inches long, so a 33-foot double roll yields 3 strips. That works out to about 9 double rolls (18 single rolls) with no pattern repeat. Large repeats can add more.
In the US, a single roll is about 20.5 inches wide × 16.5 feet long (about 28 sq ft), and a double roll is 20.5 inches × 33 feet (about 56 sq ft). Most US wallpaper is sold as double rolls but priced per single roll, so always check which one the price refers to. European rolls are about 21 inches × 33 feet and are sold as single rolls.
Pattern repeat is the distance before the design starts again. Each strip has to start at the same point in the pattern, so its length is rounded up to the next full repeat. Our calculator does this automatically, which is why large repeats can mean fewer strips per roll.
It’s generally not recommended. Old wallpaper can bubble, peel, or create an uneven surface. The adhesive from new wallpaper can also loosen the old layer. Best practice is to remove old wallpaper completely, repair the wall, and apply primer before hanging new wallpaper. If the old paper is in perfect condition and firmly bonded, a single smooth layer might work—but it’s risky.
A 12-foot wide wall needs 8 strips of 20.5-inch paper. At 8 feet tall (100-inch strips with trimming), a 33-foot double roll yields 3 strips, so you need 3 double rolls. Dividing the wall area by the roll’s square footage would suggest 2, which comes up short. In the calculator, enter half the wall width as the room length and 0 as the width.
In the US, a single roll is about 20.5 inches wide × 16.5 feet (about 28 sq ft) and a double roll is 20.5 inches × 33 feet (about 56 sq ft). European rolls are typically 21 inches × 33 feet. Wide rolls (27 or 36 inches) cover more area per strip and mean fewer seams but are heavier to handle.