What is this?
The Wallpaper Calculator determines how many rolls of wallpaper you need for a room by calculating net wall area (after subtracting doors and windows) and adding a waste allowance that accounts for pattern repeat, trim loss, and installation errors.How to use
Enter room dimensions (length, width, ceiling height), roll dimensions (width and length from the product label), and the pattern repeat in inches (found on the label; 0 for no pattern). Add number of doors and windows. The calculator shows rolls needed and rounds up to pairs since wallpaper is sold in double-roll units.Tips
- Always buy 1–2 extra rolls from the same dye lot number — color can vary between batches and discontinued patterns become unavailable.
- Large pattern repeats (18"+ drop) can waste 25–50% of a roll; account for this when budgeting materials.
- Measure ceiling height from floor to cornice or molding, not to the raw ceiling, for accurate calculations.
- European double rolls (27" wide) cover more area per roll than standard US single rolls (21" wide) — confirm which type you're buying.
- Prep walls thoroughly: fill holes, sand smooth, and apply a wallpaper primer sealer for best long-term adhesion.
- For peel-and-stick wallpaper, add an extra 15–20% waste since repositioning after sticking is limited.
- Start hanging from the most visible wall (usually opposite the door entry) so any pattern mismatch falls in corners.
