How to use this calculator
- 1Enter the room size, or the total width of the walls you want to paper.
- 2Enter the wall height from skirting to ceiling.
- 3Pick your roll size and enter the pattern repeat from the label.
- 4Only take off very wide openings; strips above and below doors and windows still use most of a strip.
The formula
- 01Strips needed = wall width ÷ roll width, rounded up
- 02Strip length = wall height + pattern repeat + trim
- 03Strips per roll = roll length ÷ strip length, rounded down
- 04Rolls = strips needed ÷ strips per roll, rounded up
Wallpaper is hung in vertical strips, and each strip must be a whole piece. That is why decorators count strips, not square metres: the offcut at the end of a roll is often too short to use.
A pattern repeat means each strip has to start at the same point in the pattern, so up to one repeat is lost per strip.
Worked example
A 4 m × 3 m room has 33.6 m² of wall at 2.4 m high.
That takes 27 strips of 2.5 m. A standard roll gives 4 strips, so you need 7 rolls.
Tips before you buy
- Large repeats (over 50 cm) waste much more paper — the calculator accounts for this.
- Paper the most visible wall first so any pattern join ends up in a quiet corner.
- Keep the label from one roll: it has the batch number you'll need if you ever buy more.
Frequently asked questions
What is a standard wallpaper roll size?
In the UK and Europe most rolls are 10.05 m long and 53 cm wide (about 5.3 m²). In the US, a double roll is usually 20.5 in wide and 33 ft long (about 56 ft²).
Why not just divide the wall area by the roll area?
Because each strip must be one piece from floor to ceiling. The leftover at the end of a roll is often too short, so the strip method gives the true number.
Do I subtract doors and windows?
Normally no — you still need strips above and below them, and the extra paper is useful. Only subtract very wide openings like patio doors.
Also searched as: wallpaper roll calculatorhow much wallpaper do I needwallpaper estimator
Sources
- Roll sizes: standard UK/EU (10.05 × 0.53 m), US double roll (20.5 in × 33 ft), German 70 cm rolls (10.05 × 0.70 m) and Korean/Chinese wide rolls (15.6 × 1.06 m, about 16.5 m²). Method: decorators' strip count.
- Paste: packets state how many standard rolls they hang; the calculator starts at a cautious 5 rolls per packet.
Formulas last reviewed: September 30, 2026 ·How we check our formulas