About the Wallpaper Calculator
Enter the room dimensions and the usable coverage per roll to get the number of rolls, with a waste allowance for pattern matching and trimming. Large pattern repeats waste more.
How it’s calculated
Rolls = (wall area − openings) × (1 + waste%) ÷ usable coverage per roll, rounded up.
Example calculation
A 14 × 12 ft room with 9 ft walls, 28 sq ft usable per roll, and 15% waste needs about 20 rolls.
Frequently asked questions
Why is usable coverage less than the roll size?
You trim the top and bottom of each strip to match the pattern, so the usable area is less than the roll's total. Bigger repeats waste more — allow extra.
Should all rolls be from the same batch?
Yes — buy them together with the same batch number so colours and patterns match exactly.
This is a general material estimate for planning only. Actual quantities vary with waste, offcuts, site conditions, product coverage, and technique. Confirm measurements and coverage rates before ordering, follow local building codes, and round up — running short mid-project is costly.