Wallpaper Calculator
The Wallpaper Calculator estimates how many rolls you need based on your wall size and standard roll dimensions, with an adjustable waste allowance for pattern matching.
Advertisement
Advertisement
How This Tool Works
Enter your total wall length and height, along with your wallpaper roll's dimensions, to calculate how many rolls to order.
Formula & Method
Roll coverage (sq ft) = (roll width in inches ÷ 12) × roll length in feet. Rolls needed = (wall area × (1 + waste%)) ÷ roll coverage.
Example Calculation
A 20 ft long, 8 ft high wall (160 sq ft) using standard 20.5 in × 33 ft rolls (about 56 sq ft each) with 15% waste needs about 4 rolls.
Frequently Asked Questions
Why is the waste factor higher for wallpaper than paint?+
Wallpaper often has a repeating pattern that must line up between strips, which wastes more material than a solid paint color — 15% is a safe default, more for large repeats.
Should I subtract doors and windows?+
For a rough estimate you can skip small deductions, since offcuts from door and window areas often get reused above or below openings. For precision, measure each wall segment individually.
What if my rolls are a different size?+
Just update the roll width and length fields — the calculator will recompute the coverage per roll automatically.
Advertisement
Related Tools
Paint Calculator
Estimate how many gallons of paint you need for any room.
Use tool →Home & GardenDrywall Calculator
Calculate how many sheets of drywall you need for walls and ceilings.
Use tool →ConstructionSquare Footage Calculator
Quickly calculate square footage, square yards, and acres.
Use tool →Home & GardenFlooring Calculator
Calculate how much flooring material to buy, including waste allowance.
Use tool →