Wallpaper Roll Calculator
Drops and rolls from perimeter, height and pattern repeat.
Inputs
Result
Formula
| Cut length | L = wall height + pattern repeat (0.1 m trim if plain) |
| Drops per roll | n = floor(roll length ÷ L) |
| Drops needed | N = ceil(perimeter ÷ roll width) |
| Rolls | R = ceil(N ÷ n) |
An 18 m perimeter at 2.8 m with 0.53 × 10 m rolls and no repeat: 2.90 m per drop, 3 drops per roll, 34 drops, so 12 rolls. At a 0.64 m repeat each drop is 3.44 m, only 2 fit per roll, and 17 rolls are needed.
FAQ
Why does a pattern repeat cost so much extra?
With a repeat every drop must start at the same point in the pattern: a 2.8 m wall plus a 0.64 m repeat is 3.44 m, so a 10 m roll yields two drops and leaves 3.12 m unusable. That is why large repeats waste so much. Calculate with this formula rather than dividing area, or you will run short.
Can I deduct doors and windows?
Rarely, because paper is hung in full drops: the strips above and below an opening are cut from a full drop and the offcut seldom matches elsewhere. You only save when a door runs full height or a window sits exactly between two drops. This tool shows net area but does not reduce the roll count.
How much adhesive?
About 1 kg of powder, once mixed, covers 20-25 m², or 0.3-0.4 kg per 5.3 m² roll. Primer is separate at roughly 8-10 m² per kg. Prime the wall first: adhesive soaked straight into the filler coat will fail in sheets later.
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Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.