How many rolls of wallpaper do I need? How to use the 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.
How to calculate wallpaper rolls (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.
Wallpaper calculation 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.
How many rolls of wallpaper for a room?
| Room (floor) | 8 ft walls | 9 ft walls | 10 ft walls | 12 ft walls |
|---|---|---|---|---|
| 10 × 10 ft | 8 | 8 | 8 | 12 |
| 10 × 12 ft | 9 | 9 | 9 | 13 |
| 12 × 12 ft | 10 | 10 | 10 | 15 |
| 12 × 14 ft | 11 | 11 | 11 | 16 |
| 14 × 16 ft | 12 | 12 | 12 | 18 |
| 16 × 20 ft | 15 | 15 | 15 | 22 |
All four walls, no pattern repeat, nothing taken off for doors and windows — worked out by the calculator with the strip method. Take off about one roll for each door or large window; add rolls for a large pattern repeat.
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.
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