Wallpaper Calculator (Rolls Needed)
Calculate wallpaper rolls needed based on room dimensions, openings, and pattern repeat.
What this calculates
Buying wallpaper means accounting for pattern repeats, drop matches, and waste. This calculator estimates double-roll quantities for standard 27-inch wide American wallpaper (one double-roll ≈ 56 sq ft usable). Always add 10-15% waste, more for large pattern repeats.
Formula & how it works
Wall area = perimeter × ceiling height. Subtract openings (door ≈ 21 sq ft, window ≈ 15 sq ft). Add waste % for pattern. Rolls = ceil(wall area ÷ 56) for double-rolls.
Worked example
12 × 14 room, 8 ft ceiling, 2 doors + 2 windows, 6" pattern repeat. Perimeter 52 ft. Wall area 416 sq ft − 72 (openings) = 344. +15% waste = 396. Rolls = ceil(396 ÷ 56) = 8 double-rolls.
Frequently asked questions
Single vs double roll?
American wallpaper is priced per single roll but packaged as doubles (~56 sq ft). European rolls are different — check the label.
Pattern repeat impact?
Repeats < 6" need ~10% waste, 13-19" need 20-25%, drop-match patterns can need 30%+.
Mural / panel wallpaper?
Sold per panel sized to your wall — don't use this calculator. Measure precisely and add 2-3 inches all around.