Wallpaper Pattern Match Calculator

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:

1. Random match (no pattern): No waste from matching. Simply calculate wall area and divide by roll coverage.

2. 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.

3. 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.

This calculator counts strips rather than dividing wall area by roll area:

Strips needed = Room Perimeter ÷ Roll Width, rounded UP Strip length = Wall Height + 10 cm trim, rounded UP to a whole number of repeats Strips per roll = Roll Length ÷ Strip Length, rounded DOWN Rolls = Strips needed ÷ Strips per roll, rounded up, then a 10% buffer on top

Rounding the strip length UP is the whole point of pattern matching. Every strip has to begin at the same place in the design, so a strip that needs 2.6 m of a paper with a 0.64 m repeat is cut at 3.2 m, five full repeats, and the leftover 0.6 m is offcut. For a half-drop, add half a repeat before rounding up, because alternate strips start half a repeat down the design.

Two rooms with identical wall area can need different numbers of rolls. A roll that yields three strips and a roll that yields two hold the same square footage and are not the same purchase, which is why the area method is only ever a first estimate. If you want the area version, the Wallpaper Calculator does it that way, at 10% waste for a random match, 15% straight and 25% drop.

Roll dimensions vary by manufacturer and country. Enter the roll length and width in whichever unit you picked above, feet or metres, and the calculator handles the rest:

• European standard: 10 m × 52 cm = 5.2 m² per roll (56 sq ft)
• US double roll: 27 ft × 27 inches (2.25 ft) = 60.75 sq ft per roll (5.64 m²)
• Some UK rolls: 10 m × 53 cm = 5.3 m² per roll (57 sq ft)

Working in feet? Enter the roll width in feet too, so 27 inches goes in as 2.25.

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.