Wallpaper Rolls Room
Calculator
Results
- Strip length including repeat (m)
- 2.5
- Strips needed
- 34
- Strips per roll
- 4
- Rolls needed
- 9
- Wall area (m²)
- 45
Craft results
| Strip length including repeat (m) | 2.5 |
| Strips needed | 34 |
| Strips per roll | 4 |
| Rolls needed | 9 |
| Wall area (m²) | 45 |
formula-map diagram
- Strip length including repeat (m)
- 2.5
- Strips needed
- 34
- Strips per roll
- 4
- Rolls needed
- 9
- Wall area (m²)
- 45
Formula breakdown
Formula
rolls = ceil(strips needed ÷ floor(roll length ÷ strip length))= 2.5
Note
Simplified model: these are standard craft estimates based on rectangular layouts, quoted gauge and nominal densities. Real fabric nap, directional prints, shrinkage, pattern matching, yarn lots and supplier SAP values vary, so always make a swatch or test piece and buy a little extra.
More in Crafts and sewing
See all →Frequently asked questions
Why do I need more rolls than the simple area-divided-by-coverage math suggests?+
Pattern repeat forces you to cut each drop longer than the wall height to align the pattern between strips, and cutting drops from a roll rarely uses 100% of it without waste, so a repeat and waste allowance is added on top of the basic area calculation.
How does pattern repeat size affect roll count?+
A larger repeat (the vertical distance before the pattern repeats) wastes more per drop, since each cut must start at the right point in the pattern, discarding the leftover; a 24-inch repeat wastes noticeably more per drop than a plain or small-repeat pattern.
Should I subtract door and window area from the total?+
Only partially: most installers don't subtract small to medium openings because leftover cut drops around them are usually too short to reuse elsewhere, so the material savings are minimal; only subtract large openings and even then keep a margin.
Why does the calculator round up to a whole number of rolls?+
Wallpaper is sold by the roll, and rolls from different production batches (run numbers) can have slight color variation, so buying an extra full roll from the same run is safer than buying a partial roll or ordering a mismatched batch later.
Does ceiling height matter beyond just the wall area?+
Yes, taller ceilings mean fewer drops per roll since each drop is longer, so the same wall area on a 10-foot ceiling needs proportionally more rolls than on an 8-foot ceiling, not just because of more area but because of fewer drops per roll.