Before buying wallpaper, use this calculator to get the number of rolls you need from the actual wall length, ceiling height and pattern type. It includes cutting waste and pattern matching, which usually accounts for most of the surplus rolls.
Methodology
This calculator produces an indicative estimate based on the parameters you enter. The ranges used reflect typical market tiers in the decor and storage space and are neither a commercial offer nor a guarantee. Prices and availability may vary.
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Frequently asked questions
How many rolls for a 20 m² room?
For a square 20 m² room (about 18 m of wall, 2.5 m high and 3 m² of openings), expect 8 to 10 rolls of 0.53 × 10 m depending on the pattern. Enter your own measurements for the exact figure.
Should I add an extra roll?
The calculator already applies 10% waste for plain paper, 15% for a straight match and 22% for an offset match. One spare roll is still useful for touch-ups.
Why does the pattern change the number of rolls?
A repeated pattern forces the strips to be aligned, so more is cut away. The more the repeat is offset, the lower the usable area per roll.