Quick brief
What to know before you calculate
A short read on the assumptions, trade-offs and definitions that shape the answer.
- Measure total wall width and height before subtracting large openings.
- Pattern repeat and batch matching can increase the number of rolls needed.
- Buying spare rolls from the same batch is often safer than reordering later.
Measure the wall area
Add the widths of the walls being papered and multiply by wall height. Large doors or windows can be subtracted if you know their area, but do not remove every small opening if it makes the estimate too tight. Offcuts still matter.
Check roll coverage
Wallpaper rolls vary by width and length. Coverage based only on square metres is a useful estimate, but patterned paper may need more because each drop has to line up. The product label or supplier guidance is important for patterned designs.
Allow for waste
Waste comes from trimming, mistakes, damaged sections, corners and matching the pattern. A plain paper in a simple room may need a smaller allowance than a large repeat pattern in a room with many doors, windows and alcoves.
Keep batch numbers together
Wallpaper can vary slightly between batches. If you need extra rolls later, the colour may not match perfectly. Ordering a sensible spare amount at the start can prevent visible differences on the wall.
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