Wallpaper Calculator
Estimate wallpaper rolls from wall size, roll width and length, and pattern repeat. Includes openings and a recommended extra.
How to use this wallpaper calculator
Wallpaper is ordered in rolls, not gallons. Pattern repeat is the vertical distance before the design lines up — a 21-inch repeat wastes a lot of each drop compared with a solid texture. Measure each wall, add them as length × walls, and use the actual roll label for width and length.
Doors and windows still leave strips around the opening, so this wallpaper calculator keeps the strip count from full wall width and only uses openings for the net-area figure. Always buy from the same dye lot. Leftover rolls are cheaper than a mismatch in two years.
Formula
Worked example
Four 12 ft walls, 8 ft high, 20.5 in × 33 ft rolls, no repeat: 48 ft ÷ 1.708 ft ≈ 29 strips. 33 ÷ 8 = 4 strips/roll → 8 rolls. 10% extra → 9 rolls.
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Frequently asked questions
How many rolls of wallpaper do I need?
Count strips across all walls, see how many full drops fit on one roll after pattern repeat, divide, then add 10%.
What is a pattern repeat?
The vertical length of one full design. Enter 0 for textures with no match.
US vs European rolls?
US “American” rolls are often ~20.5 in × 33 ft (about 56 sq ft). Euro rolls are often 53 cm × 10 m. Switch Units for meters and centimeters.
Do I subtract windows?
Openings save paper in theory, but you still cut around them. Do not under-order; the recommended rolls include waste.
Pre-pasted vs unpasted?
Same roll count. Paste and liner are extra.
Results are estimates for informational purposes and are not financial, legal, or professional advice. Last reviewed 2026-08-19.