Wallpaper Calculator
Last updated: 12 August 2026
Work out how many rolls of wallpaper you need for a room. Unlike most calculators, this one handles pattern repeat properly — the single biggest reason people run out of paper mid-job.
How the calculation works
Drops = wall perimeter ÷ roll width (52cm on a standard UK roll). Each drop needs the wall height plus about 100mm for trimming top and bottom.
Pattern repeat is where most calculators fail. If the paper has a 53cm repeat, every drop must be cut to a whole number of repeats — so a 2.5m drop becomes 3 repeats (1.59m) … no, it rounds up to the next whole repeat above your drop length, which can waste up to a full repeat per drop. We round the drop length up to the next whole repeat, then work out how many of those fit in a roll.
Rolls per room at a glance
| Room size (2.4m ceiling) | Plain / free match | 53cm repeat |
|---|---|---|
| 3 × 3m | 6 rolls | 8 rolls |
| 4 × 3m | 7 rolls | 9 rolls |
| 4 × 4m | 8 rolls | 10 rolls |
| 5 × 4m | 9 rolls | 11 rolls |
Figures assume 2.4m ceilings and one door deducted. Note how much a large repeat costs you — two extra rolls on an average room, because each drop is cut longer to align the pattern.
Buy from one batch
Always order all your rolls in one go and check the batch number on every one. Colours drift noticeably between print runs, and a mid-wall batch change is obvious under daylight. Buy one spare roll — it costs far less than discovering the batch is discontinued halfway through.
Frequently asked questions
How many rolls of wallpaper do I need?
For an average 4m x 3m room with 2.4m ceilings and one door, allow about 7 rolls of plain or free-match paper. A large 53cm pattern repeat pushes that to 9 rolls, because each drop must be cut to a whole number of repeats.
How long is a roll of wallpaper?
A standard UK roll is 10.05 metres long and 52cm wide, giving about 5.2 square metres. Some designer papers come as 15m long rolls. Always check, because roll sizes vary by manufacturer.
What is pattern repeat and why does it matter?
Pattern repeat is the vertical distance before the design starts again. Each drop must be cut to a whole number of repeats so the pattern lines up, so a large repeat can waste up to half a metre per drop — which is why a 53cm repeat typically adds about two rolls to an average room.
How many drops can I get from one roll?
With a 2.4m ceiling and no pattern repeat, four drops per 10.05m roll. With a large repeat you often get only three, because each drop is cut longer to align the pattern.
Should I buy an extra roll of wallpaper?
Yes. Buy one spare from the same batch. Batch colours vary between print runs, and papers get discontinued — a spare roll is cheap insurance against a damaged wall later.
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Lengths of skirting for a room, with mitre wastage.
Estimates are for guidance only. Material dimensions, densities and coverage vary by supplier — always confirm quantities before ordering, and consult a qualified professional for structural work.