Calculate exactly how many wallpaper rolls you need based on room dimensions, openings, and wallpaper specs. All processing happens locally in your browser — no data uploaded.
The Wallpaper Calculator is a home improvement tool that helps you calculate exactly how many rolls of wallpaper you need, avoiding both overbuying and underbuying.
Measure the total length of all four walls (perimeter) and the ceiling height with a tape measure. If you have multiple walls, add their lengths together for the perimeter.
Measure all door and window areas that don't need wallpaper. Add them together and enter the total in the "Door & Window Area" field. The tool automatically subtracts this from the total wall area.
Check the wallpaper packaging for width and roll length specifications. The most common standard is 0.53m wide and 10m per roll. Select the appropriate waste factor based on pattern complexity.
Click "Calculate Wallpaper" to see the number of rolls needed, estimated cost, and detailed breakdown including wall area, per-roll coverage, and waste area.
Formula: Net area = Perimeter × Height − Door/Window area. Rolls needed = ⌈Net area × Waste factor ÷ Per-roll coverage⌉.
Waste Factor: Wallpaper installation requires pattern matching, cutting, and corner handling, which inevitably produces waste. No match: 5%, simple pattern: 10%, complex pattern: 15%, large pattern: 20%.
Recommendation: Buy 1-2 extra rolls for future repairs, as different production batches may have slight color differences.
The most common wallpaper standard is 0.53m wide and 10m per roll, covering approximately 5.3m². Wide-format wallpapers (0.7m or 1.06m) are also available.
Doors and windows don't need wallpaper, so their area is subtracted to reduce waste. However, trimming around openings still produces some waste, which is included in the waste factor.
This tool uses standard formulas for reference. Actual usage may vary based on wall condition and installation technique. We recommend buying 1-2 extra rolls.