Wallpaper Rolls Calculator
Enter your wall area, roll coverage and a waste allowance to find out how many whole rolls of wallpaper to buy.
Wallpaper Rolls Calculator
Calculates how many whole rolls of wallpaper you need for a wall area, including a waste allowance.
This calculator first adds a waste allowance percentage to your raw wall area to account for pattern matching, trimming and mistakes, then divides that adjusted area by your wallpaper roll's coverage and rounds the result up to the next whole roll, since rolls can't be purchased in fractions. Using an explicit waste allowance (higher for bold repeating patterns, lower for plain wallpaper) helps avoid the common problem of running one roll short mid-project.
Example
- With the default values shown above, this calculator returns: Adjusted Area (with waste) ≈ 33 m²; Raw Roll Count ≈ 6.6; Rolls to Buy ≈ 7 rolls.
Frequently Asked Questions
Why is the waste allowance so important for wallpaper?
Patterned wallpaper especially needs extra material for aligning repeats across seams, plus trimming at ceilings, floors and around openings, so builders commonly add 10% or more compared to the raw wall area.
Why does the roll count always round up?
You can't buy a fraction of a roll, so the calculator always rounds up to the next whole roll to make sure you have enough material, even if that means a small amount of leftover paper.
Sources
- Standard formula, publicly documented method