Wallpaper Calculator
By Santaji GadepatilinUpdated October 27, 2026
Wallpaper is sold in rolls of fixed width and length. The number of rolls depends on the room's perimeter, wall height and the pattern repeat.
How to use the wallpaper calculator
Enter the wall length to cover, wall height, roll width and length, and the pattern repeat (0 for plain paper). The number of strips, strips per roll and rolls needed are calculated. 10 cm per strip is allowed for trimming.
Example
14 m of wall, 2.5 m high, standard 53 cm × 10 m rolls, no repeat:
- Drops = 14 ÷ 0.53 → 27
- Drops per roll = 10 ÷ 2.6 → 3
- Rolls = 9
Buy all rolls from the same batch number so the colour matches.
Rolls needed by room
Standard 0.53 × 10 m rolls, 2.5 m walls, no pattern repeat:
| Room perimeter | Drops | Rolls |
|---|---|---|
| 10 m | 19 | 7 |
| 12 m | 23 | 8 |
| 14 m | 27 | 9 |
| 16 m | 31 | 11 |
| 18 m | 34 | 12 |
| 20 m | 38 | 13 |
Pattern repeat
A pattern repeat means each drop must be cut longer so the pattern lines up. Large repeats (over 50 cm) can waste a lot of paper — sometimes a whole drop per roll.
| Match type | What it means |
|---|---|
| Free match | No pattern alignment, least waste |
| Straight match | Pattern aligns horizontally across drops |
| Offset (drop) match | Pattern shifts by half a repeat on alternate drops |
Roll sizes
| Type | Typical size |
|---|---|
| Standard European roll | 0.53 × 10.05 m |
| US double roll | about 0.53 × 10 m (sold as two single rolls) |
| Wide roll | 0.70 × 10 m |
Windows and doors
Most decorators do not subtract windows and doors from small rooms, because partial drops above and below them still use up paper. For large openings, subtract one drop per full-width door.
Batch numbers
Buy all rolls with the same batch number, as colours can vary between print runs. Buy one extra roll for repairs.
Frequently asked questions
What size is a standard wallpaper roll?
In Europe and the UK, usually 53 cm × 10.05 m. US rolls vary; check the label.
What is a pattern repeat?
The vertical distance before the pattern repeats. Larger repeats waste more paper when matching strips.
Should I subtract doors and windows?
Usually not — the offcuts rarely fit elsewhere, and spare paper is useful for repairs.
How many rolls of wallpaper for a 4 × 4 m room?
With 2.5 m walls and no repeat, about 31 drops — 11 standard rolls at 3 drops per roll.
How many drops are in a roll?
For 2.5 m walls, a 10 m roll gives 3 full drops (plus a short offcut).