Wallpaper Calculator

Divide the room perimeter by the roll width to get the number of strips, then divide the roll length by your wall height plus one pattern repeat to see how many strips each roll gives. Divide strips needed by strips per roll and round up.

A standard European roll is 0.53 x 10.05 m, about 5.3 m² or 57 sq ft. A US double roll covers about 56 sq ft, but usable coverage is usually 15–25% less after trimming and pattern matching.

Each strip must be cut longer by up to one full pattern repeat so the design lines up. Large repeats of 18 in or more can increase the number of rolls by 10–25%.

Subtract large openings like doors and wide windows, but not small ones, since the trimmed waste around them is rarely reusable. When in doubt, keep the openings in the calculation for a safety margin.

Buy at least one extra roll, or about 10–15% more, from the same batch number. Rolls from different batches can vary slightly in color, which shows on the wall.