Wallpaper Calculator
Enter your total wall area, the coverage of your chosen wallpaper roll, and a waste allowance for pattern matching to calculate how many rolls to buy.
How the Wallpaper formula works
A coverage-based calculation with waste built in:
Rolls needed = ceil( Wall area × (1 + Waste%) / Roll coverage )
Step-by-step calculation
- Calculate total wall area to be papered (perimeter × height, minus large openings if desired).
- Increase that area by your waste percentage to account for pattern matching and trimming.
- Divide by a single roll's coverage area and round up to a whole roll.
Worked example
A room with 320 ft² of wall area, using rolls that cover 56 ft² each, with a 15% waste allowance for pattern matching: Rolls = ceil(320 × 1.15 / 56) = ceil(6.57) = 7 rolls.
Frequently asked questions
Why is waste allowance higher for wallpaper than paint?
Patterned wallpaper needs to line up between strips, which means cutting extra material to match the repeat — the bigger the pattern repeat, the more waste is typical. Plain or textured wallpapers need less allowance, often closer to 10%.
Does roll size vary?
Yes — 'single' and 'double' rolls are common, with double rolls covering roughly twice the area. Always check the specific coverage printed on your chosen wallpaper's packaging rather than assuming a standard size.