calcs.homes
calcs.homes
Enter the room size, wall height, your roll's width and length, and the pattern repeat, and this wallpaper calculator estimates the rolls to order.
Estimate only — a large pattern repeat can waste far more than the flat allowance here.
We work out the net wall area (perimeter times height, minus doors and windows), then the area one roll covers — roll width times roll length. A plain or random-match paper wastes little, so we credit about 95% of a roll; a paper with a set pattern repeat wastes more at the top of every strip, so we credit about 85%. Net area plus your waste allowance, divided by that usable coverage, rounded up, gives the roll count.
Wallpaper is sold as single rolls but very often packaged and hung as double rolls, so check which you are pricing. Always order every roll from the same batch or run number — color shifts between batches are visible on a wall — and keep a spare roll for future repairs, since patterns are discontinued often.
Find the net wall area, add 15% for waste, and divide by the usable coverage of one roll (about 25–30 sq ft usable for a US double roll). Round up and add one spare.
Yes. A 20-inch repeat means every drop is cut to a common start point, and the offcut at the top — up to nearly a full repeat — is waste. Large repeats can add 20–30% to the order.
Wallpaper is priced per single roll but usually bolted as a double roll for less waste. Confirm which the price and the coverage refer to before ordering.