Wallpaper is hung in vertical strips (drops), so the number of rolls depends on how many full-height strips you can cut from each roll — not just the wall area. Enter your wall size, roll size and pattern repeat for an accurate count.
Doors and windows are not subtracted: the off-cuts are rarely usable, so most decorators ignore small openings. Buy all rolls from the same batch number so the colour matches.
Formula
Rolls = ⌈ ⌈Wall width ÷ Roll width⌉ ÷ ⌊Roll length ÷ (Height + Repeat + Trim)⌋ ⌉
A 10 cm (4 in) trimming allowance is added to every strip.
Worked example
A room with 14 m of wall, 2.4 m high, using standard 0.53 × 10.05 m rolls with no repeat: each strip is 2.5 m, so a roll gives 4 strips. The walls need ⌈14 ÷ 0.53⌉ = 27 strips, which is 7 rolls.
Frequently asked questions
How many rolls of wallpaper do I need for a room?
An average bedroom (14 m or 46 ft of wall, 2.4 m or 8 ft high) needs about 7 standard European rolls. Large pattern repeats can add one or two more.
What is a pattern repeat?
The vertical distance before the pattern repeats. Strips must be aligned to it, which wastes some paper on every drop.
Last updated · Calculations checked by automated tests· Editorial policy