After many decades of diminished interest by interior decorators and homeowners, wallpaper has been making a strong comeback in recent years. According to surveys conducted by Architectural Digest and Houzz, the global wallpaper market is expected to reach a $4 billion valuation by 2035, reflecting a 7.4% growth. What was once sidelined as a vintage design element is turning into a modern home decor powerhouse that allows you to add rich textures, interesting patterns, and visual appeal to any room.
As one of the most satisfying do-it-yourself (DIY) home improvement projects, applying wallpaper gives you an opportunity to express personal style, create accent walls, and transform living spaces into focal points. Starting a wallpaper project is fun; you can browse Better Home & Gardens, Pinterest, Instagram, and Spoonflower for design ideas that will guide you toward the material and brand. Then, you can gather the tools you’ll need for the project before taking measurements and calculating the budget. You’ll need our wallpaper measurement guide for the next step, which will help you obtain the precise calculations required for a flawless installation.
Estimating Wallpaper Quantities Accurately
Precise measurements and calculations are crucial because even small mathematical errors can disrupt your entire installation. Underestimating can result in running out of a specific batch or roll mid-project. You should always overestimate slightly, but not so much as to waste materials and go over budget. Mastering this step is at the heart of our wallpaper measurement guide, for which you’ll need a tape measure, ruler, pencil, paper or a smartphone app for taking notes, and our online wallpaper roll calculator. You may also need a step stool or ladder for floor-to-ceiling projects.
Measuring Wall Dimensions
In the North American market, wallpaper is measured in imperial units (feet and inches). If you plan on sourcing the material directly from brands such as Graham & Brown or Sangetsu, which use the metric system, you’ll need to make conversions using the standard factors below:
* To convert inches to centimeters, multiply by 2.54. For example, 20.5 in X 2.54 = 52.07 cm.
* To convert feet to meters, multiply by 0.3048. For example, 9 ft X 0.3048 = 2.74 m.
* To convert square feet to square meters, divide by 10.764. For example, 100 sq ft / 10.764 = 9.29 sq m.
After gathering the tools, the next step involves measuring the wall height and width. If your project will cover entire rooms, you should measure each wall individually to account for surfaces that aren’t perfectly symmetrical. Start by running the tape horizontally along the baseboard from corner to corner to measure the width, remembering to multiply inches by 12 to calculate feet.
Interior decorators and contractors always double-check their measurements before writing them down. This is fundamental to prevent oversight errors. After measuring, double-checking, and recording the widths, proceed to measure height vertically, starting from the top of the baseboard to the bottom of the ceiling trim or crown molding. The best practice for measuring height is to run the tape at three separate points along the wall: left, center, and right. Double-check each measurement and make a note of the highest dimension to account for uneven ceilings.
Calculating the Baseline Area
Your height and width measurements can be converted to square footage with a multiplication:
Wall Area = Width (ft) X Height (ft)
The gross square footage is the sum of the individual walls:
Gross Total Area = Wall 1 + Wall 2 + Wall 3 + Wall 4
Considering the Pattern Repeat Factor
This factor is unique to wallpaper projects. Unlike painting, hanging wallpaper requires alignment from strip to strip. If the material you select features a specific pattern repeat, which is the vertical distance between the design element repeating down the roll, you will need to use the formula below for adjustment:
Unrounded Strips = Wall Height (in) / Pattern Repeat (in)
Please note that the formula rounds up the wall height to the nearest multiple of the pattern repeat, which you can find on the material label or description. The most common wallpaper patterns repeat at 6, 12, and 24-inch intervals. We’ll include this factor when we review the measurements with an example calculation below, after accounting for waste, doors, windows, slopes, and staircases.
Accounting for Wallpaper Waste
North American standard wallpaper is typically packaged as a “double roll” covering approximately 56 sq ft. With pattern-matching cuts, the realistic coverage is up to 30 sq ft. To avoid running short, calculate your baseline square footage and add 10% as a waste allowance for cuts, trimming, and alignment errors. With this waste margin, you can order sufficient material to finish seamlessly.
Doors, Windows, Slopes, and Staircases
You can safely ignore standard doors and windows when measuring for wallpaper projects. If your project features sloped walls, remember to measure at the highest and widest points, adding 4 in for a safe trimming margin. We recommend doing the same for staircases. Generally, it is better to cut away excess material than to come up short.
Example DIY Wallpaper Project Calculation
Let’s say your height is 102 inches (8.5 ft) and your wallpaper has an 18-inch floral vertical pattern repeat, like a York Peacock Garden roll:
102 in / 18 in = 5.67 in, which you can round to 6 in
6 in X 18 in = 108 in, which is 9 ft
Your effective wall height for ordering is 9 feet per strip. Now, let’s assume you are papering a square room with four walls measuring 10 ft each:
Adjusted Total Area = 40 ft (total width) x 9 ft (adjusted height) = 360 sq ft
A York Peacock Garden double roll measures 21 in wide and 33 ft long, which is approximately 56 sq ft of usable coverage:
360 ft / 56 sq ft = 6.42 rolls, which you should round to 7 rolls for the pattern repeat and waste factors.
For accuracy and convenience, our Wallpaper Roll Calculator allows you to input the wall height and width in feet, the standard roll width in inches and length in feet, and the optional pattern repeat in inches. With precise measurements and roll counts, you can continue the project. Pick your favorite pattern, grab your tools, and get ready to transform your living spaces.