Introduction
Figuring out how many rolls of wallpaper you need can be tricky. Buy too few and you'll run short mid-project. Buy too many and you waste money. This wallpaper calculator takes the guesswork out of your next wall covering job by doing the math for you in seconds.
Enter your room dimensions, door and window sizes, and wallpaper roll specs, and the calculator tells you exactly how many rolls to buy. It works in two modes: a simple mode where you enter the total wall perimeter, and an advanced mode where you measure each wall separately. The tool also accounts for pattern repeats, adds a waste factor for cuts and mistakes, and estimates your total cost. You can switch between imperial and metric units with one click, so it works no matter where you are.
How to Use Our Wallpaper Calculator
Enter your room measurements, door and window details, and wallpaper roll specs below. The calculator will tell you how many rolls of wallpaper you need and the estimated cost for your project.
Unit Toggle (Imperial / Metric): Choose between Imperial (feet and inches) or Metric (meters and centimeters) units. The calculator will convert all your values automatically when you switch.
Simple or Advanced Mode: Use Simple mode to enter the total wall perimeter and ceiling height for the whole room. Use Advanced mode to enter the height and width of each wall one by one, which is helpful for rooms with walls of different sizes.
Total Wall Width / Perimeter (Simple Mode): Enter the combined length of all your walls added together. For a rectangular room, this is two times the length plus two times the width. If you need help determining the total area of your room, our square footage calculator can assist.
Ceiling Height (Simple Mode): Enter the distance from the floor to the ceiling.
Individual Wall Dimensions (Advanced Mode): Enter the height and width of each wall separately. Click "Add Wall" to include more walls or "Remove Wall" to delete one.
Number of Doors: Use the plus and minus buttons to set how many doors are in the room. Doors are subtracted from the total wall area so you do not buy extra wallpaper.
Door Height and Width: Enter the average height and width of your doors. The default values are based on a standard door size.
Number of Windows: Use the plus and minus buttons to set how many windows are in the room. Like doors, windows are subtracted from the wall area.
Window Height and Width: Enter the average height and width of your windows.
Roll Width: Enter the width of one wallpaper roll. A common standard roll width is 20.5 inches (52 cm).
Roll Length: Enter the length of one wallpaper roll. A common standard roll length is 33 feet (10 meters).
Pattern Repeat: Enter the distance between repeating patterns on the wallpaper. If your wallpaper has no pattern or is a solid color, leave this at 0. A pattern repeat means more wallpaper is used per strip to line up the design.
Waste Factor: Enter a percentage to account for cutting waste, mistakes, and future repairs. Use 10% for plain wallpaper and 15% for patterned wallpaper.
Cost Per Roll (Optional): Enter the price of one roll of wallpaper. If you fill this in, the calculator will show an estimated total cost for your project.
Results: After you click "Calculate Wallpaper," the tool displays the total wall area, door and window deductions, net wall area, area with waste added, usable area per roll, total number of rolls needed, strips per roll, total strips needed, and estimated cost. A donut chart also shows a visual breakdown of your wallpaper area versus deductions.
Wallpaper Calculator – Estimate Rolls, Cost, and Coverage
Figuring out how much wallpaper you need before you start a project saves you time, money, and frustration. This wallpaper calculator tells you exactly how many rolls to buy based on your room size, door and window openings, and the specific wallpaper roll you plan to use.
How Wallpaper Is Sold and Measured
Wallpaper is sold in rolls. In the United States, a standard single roll is about 20.5 inches wide and 33 feet long, covering roughly 56 square feet. A double roll is twice that length. In other countries, common metric rolls are 53 centimeters wide and 10 meters long. Always check the label on your wallpaper, because roll sizes vary by manufacturer and style.
Why You Need More Wallpaper Than the Bare Wall Area
You cannot use every inch of a wallpaper roll. Here is why you always need extra:
- Cutting waste: Each strip must be cut to match your ceiling height. The leftover piece at the bottom of the roll is often too short to use as a full strip.
- Pattern repeat: If your wallpaper has a pattern, each strip must line up with the one next to it. This means you cut away extra paper at the top or bottom of every strip to align the design. A larger pattern repeat creates more waste.
- Mistakes and damage: Tears, miscuts, and paste errors happen. A waste factor of 10% is standard for plain wallpaper. For wallpaper with a pattern repeat, bump that up to 15% or more.
What Is Pattern Repeat?
Pattern repeat is the distance between one point in the design and the next identical point directly below it. For example, a floral wallpaper might repeat its pattern every 21 inches. When you hang each strip, you have to shift the paper up or down so the flowers match across the seam. The bigger the repeat, the more paper you waste per strip. If your wallpaper has no pattern or a random texture, the pattern repeat is zero.
How to Measure Your Room
Use a tape measure and follow these steps:
- Measure each wall's width from corner to corner. Add all the widths together to get the total perimeter.
- Measure the ceiling height from the floor to the ceiling. If your room has crown molding or a chair rail and you only plan to paper part of the wall, measure just that section.
- Measure your doors and windows. Record the height and width of each one. These areas get subtracted from the total because you will not cover them with wallpaper.
Simple Mode vs. Advanced Mode
The calculator offers two modes. Simple mode is best when all your walls are the same height. You just enter the total perimeter and ceiling height. Advanced mode lets you enter each wall separately, which is helpful for rooms with different wall heights, angled ceilings, or accent walls where you only want to paper one or two surfaces.
Tips for a Successful Wallpaper Project
- Buy all your rolls at once. Rolls from different production batches can have slight color differences called dye lot variations.
- Round up, not down. It is always better to have one extra roll than to run short halfway through a wall.
- Keep leftover rolls. Store an unopened roll for future repairs. Wallpaper can get scratched, stained, or damaged over the years, and matching old patterns can be impossible later.
- Prep your walls first. Wallpaper sticks best to smooth, clean, primed surfaces. Fill holes, sand rough spots, and apply a wallpaper primer or sizing before you hang the first strip. If you're working on new construction or renovations, you may also need to plan for drywall installation and insulation before wall covering begins.
Related Construction Calculators
Working on a larger renovation project? If you're considering alternative wall coverings, our tile calculator can help you estimate materials for tile accent walls or backsplashes. For floor coverings to complement your new wallpaper, check out our flooring calculator or carpet calculator. If your project involves painting some walls instead of papering them, you may find our square footage calculator useful for estimating paint coverage. For exterior or structural work like brick, concrete, or retaining walls, we have dedicated calculators for those as well. And if you're laying pavers or pouring an epoxy floor as part of the same renovation, those tools can help you plan materials and costs across the entire project.