Wallpaper Pattern Match Calculator
Calculate how many wallpaper rolls you need, including extra for pattern matching.
Accounts for straight match, drop match, and random patterns.
Wallpaper calculation is straightforward for plain (no pattern) wallpaper, but becomes more complex when your chosen wallpaper has a repeating pattern. Pattern matching wastes wallpaper because each strip must be aligned to continue the pattern across the wall.
There are three main types of wallpaper pattern matching:
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Random match (no pattern): No waste from matching. Simply calculate wall area and divide by roll coverage.
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Straight match: The pattern aligns horizontally across the wall. Every strip starts at the same point in the pattern. Typical waste is 10–20% of one pattern repeat per drop.
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Drop match (offset): The pattern repeats at an offset — usually half a repeat — so alternating strips start at different points. This creates more waste, especially for large repeats. Waste can be 30–50% for large pattern repeats.
Basic formula (no pattern): Rolls = (Wall Perimeter × Wall Height) ÷ Roll Coverage
With pattern matching: Usable length per strip = Floor (strip height / repeat) × repeat Waste per strip = strip height − usable length per strip Then add a buffer of 5–10% extra for trimming errors
Roll dimensions vary by manufacturer and country:
- European standard: 10 m × 52 cm = 5.2 m² per roll
- US standard: 27 ft × 27 inches = ~6.8 m² per roll
- Some UK rolls: 10 m × 53 cm = 5.3 m² per roll
Always buy rolls from the same production batch (check the batch number on the label). Different batches can have slight colour variations that become visible after hanging.
When in doubt, buy one extra roll. You can often return unused rolls (check the store policy), but you cannot always get the same batch later. For large-pattern wallpapers, buying 15–20% extra is strongly recommended.
This calculator covers both metric (meters) and imperial (feet/inches) measurements.