Find out how many rolls of wallpaper to buy. The calculator works in drops (full-height strips), which is how decorators estimate, and allows for pattern repeat and trimming.
Your shopping list
How to measure
- Measure the length of each wall and the height from skirting to ceiling.
- Check the roll width and length on the label. A standard European roll is 53 cm × 10.05 m; a US double roll is about 20.5 in × 33 ft.
- Check the pattern repeat on the label. Larger repeats mean more waste per drop.
The formula
Drops needed = wall width to cover ÷ roll width (round up) Drops per roll = roll length ÷ (wall height + pattern repeat + trim) (round down) Rolls = drops needed ÷ drops per roll (round up)
Worked example
A 12 × 12 ft room with 8 ft walls and one door has about 45 ft of wall to cover. With 20.5 in rolls that is 27 drops. Each 33 ft roll gives 3 drops, so you need 9 rolls.
Tips before you buy
- Buy all rolls with the same batch number, plus one spare.
- Start next to a window or door and use a plumb line for the first drop.
- Windows are not subtracted, which leaves a small margin for mistakes.
Frequently asked questions
What is pattern repeat?
The vertical distance before the pattern repeats. Each drop must line up with the next, so larger repeats waste more paper.
Do I subtract windows?
Only large openings. Small windows still need short pieces above and below, so this calculator subtracts doors only.
How much paste do I need?
One packet of paste usually hangs about 5 rolls. Paste-the-wall papers need a ready-mixed tub.
Results are estimates for planning only. Always check quantities with your supplier before you buy.