Wallpaper Calculator
Estimate wallpaper rolls from wall area and roll coverage.
Use decimals when needed. This estimate updates live and is safe to tweak before you buy materials.
Wallpaper Buying Guide
This guide helps you turn your wallpaper calculator result into a cleaner purchase plan. Use it when you want fewer return trips, better waste assumptions, and a more realistic cart.
Step 1: Check the pattern repeat
Solid colors or stripes have zero pattern repeat. Complex floral designs might repeat every 24 inches, meaning you lose up to two feet of paper per strip.
Step 2: Buy in double rolls
Wallpaper is priced by the 'single roll' but almost universally sold as a continuous 'double roll' to give you longer usable strips. Check the label carefully.
Step 3: Match the batch number
Like tile, wallpaper is printed in batches. Always ensure every roll you buy has the exact same run or batch number to avoid slight color variations on your wall.
Recommended for this job
Commonly paired tools and accessories
These are the practical extras people often forget until the last minute, especially when turning a rough estimate into a real purchase list.
Wallpaper smoothing kitWhy this helps: Common add-on that reduces last-minute store runs once the estimate is final.
Wallpaper adhesiveWhy this helps: Common add-on that reduces last-minute store runs once the estimate is final.
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Wallpaper cost planning rule of thumb
In addition to the paper, you may need a specialized wallpaper primer (sizing), adhesive paste, a smoothing tool, and sharp utility knife blades.
Understanding the Math
Formula: The basic formula for Wallpaper Calculator typically involves calculating the total area or volume (Length × Width × Depth) and dividing by the coverage of a single unit or package, then adding a waste factor (usually 10%).
Example: For example, if you have a 10x10 area and your material covers 10 square feet per unit, you need 10 units. With a 10% waste factor, you should purchase 11 units to ensure you don't run short.
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Wallpaper Calculator FAQ
What is pattern matching and why is it important?
If you buy a wallpaper with a pattern, such as flowers or stripes, the strips (wallpaper lengths) must be matched so that the pattern continues seamlessly from one strip to the next. This means you have to shift the strip up or down until the pattern aligns, which results in a piece of the wallpaper at each end having to be cut off and thrown away. This repetition is called the pattern repeat. The larger the repeat, the more waste there will be. Our calculator automatically takes this into account if you specify the pattern repeat height.
Should I apply the paste to the wall or the wallpaper?
This depends entirely on what type of wallpaper you have bought. The vast majority of modern wallpapers today are so-called 'Non-woven' wallpapers (often called paste-the-wall). For these, you should roll the paste directly onto the wall, which is much easier and less messy. Older paper wallpapers require you to apply the paste to the back of the wallpaper and let it soak for about 5-10 minutes before putting it up. Always read the instructions on the wallpaper roll carefully, as it is crucial to the result!
How do you prepare the wall before wallpapering?
The preparation is 90% of a successful wallpapering job. Even the most expensive and beautiful wallpaper will look terrible if the wall underneath is bumpy. You must first spackle over all joints, nail holes, and irregularities, and then sand the wall smooth. If you have heavily patterned or dark old wallpapers, it may be necessary to prime the wall first to prevent the old pattern from shining through the new, often lighter, wallpaper.