How many rolls of wallpaper for a 3 m × 4 m room?
8 rolls 26 drops · 4 drops a roll · 1 spare roll included
A 3 × 4 m room with walls 2.4 m (7 ft 10 in) high needs 8 rolls of standard wallpaper: 26 drops, 4 drops from each roll, plus 1 spare roll. A paper with a pattern that repeats every 53 cm, matched straight across, gives only 3 drops a roll: 10 rolls.
Wallpaper is counted in drops, not square metres. A drop is one floor-to-ceiling strip, and a roll only gives whole ones: the piece left at the end of each roll is too short to use on a full wall. That is why the answer is more rolls than the wall area alone suggests.
The pattern repeat is on the roll's label, and it changes the answer more than the room does. Every drop has to start at the same point in the pattern, so a large repeat throws away part of every roll.
Worked out for All four walls of a room 3 × 4 m (9 ft 10 in × 13 ft 1 in), 2.4 m (7 ft 10 in) high, with 1 door, and standard rolls 10.05 m × 53 cm of a paper with no pattern to match. Change the numbers
The working
- Walls round the room: 2 × (3 m + 4 m) = 14 m
- 14 m ÷ 53 cm roll width = 26.4, so 27 drops
- Less 1 drop for 1 door: 26 drops
- Each drop: 240 cm + 10 cm trim = 250 cm
- 10.05 m roll ÷ 250 cm = 4 drops per roll
- 26 drops ÷ 4 = 7 rolls, plus 1 spare = 8
Buy every roll with the same batch number, the spare too: a later batch can differ in colour.
Windows save no paper: the pieces above and below them use most of a drop.
The rules, and their sources
Standard UK wallpaper roll
A standard UK roll is 10.05 m long and 53 cm wide (about 5.3 m²). Check the label: some are 52 cm wide or 10 m long.
Shop sizes Sources: B&Q, GoodHome Kerria wallpaper (checked 31 October 2026); Which?, How to wallpaper (checked 31 October 2026); PracticalDIY, Estimating the number of rolls (checked 31 October 2026).
Trim allowance per drop
Cut each drop about 10 cm longer than the wall is high, to trim at the ceiling and the skirting.
An industry guideline Source: Which?, How to wallpaper (checked 31 October 2026).
Spare roll from the same batch
Buy every roll from one batch number, plus a spare: rolls from different print runs can differ in colour, and a later order may not match.
An industry guideline Sources: Which?, How to wallpaper (checked 31 October 2026); PracticalDIY, Estimating the number of rolls (checked 31 October 2026); Graham & Brown, How to measure for wallpaper (checked 31 October 2026).
Other rooms
The same wall height and roll each time. The last row is a paper with a pattern, which gets fewer drops out of every roll.
| Room | Drops | Rolls to buy |
|---|---|---|
| 3 × 3 m | 22 drops | 7 rolls4 drops a roll, plus 1 spare roll |
| 3 × 4 m this page | 26 drops | 8 rolls4 drops a roll, plus 1 spare roll |
| 4 × 4 m | 30 drops | 9 rolls4 drops a roll, plus 1 spare roll |
| 4 × 5 m | 33 drops | 10 rolls4 drops a roll, plus 1 spare roll |
| 5 × 5 m | 37 drops | 11 rolls4 drops a roll, plus 1 spare roll |
| 4 × 4 ma pattern that repeats every 53 cm | 30 drops | 11 rolls3 drops a roll, plus 1 spare roll |
Change the numbers
Your sizes will differ. The wallpaper calculator opens with these numbers filled in: change any of them and the answer, the working and the drawing follow.
Editorial notes
Worked out by the Snuug team on 12 November 2026 with the same code as the wallpaper calculator, so the two cannot disagree. Every rule cites its source, with the date we last checked it. A rule designers use is a convention, not a study.
Other sources the calculator draws on:
- Howarth Timber (Green, 14 Sep 2026), UK door sizes, checked 31 October 2026