How to Calculate Wallpaper Rolls
Quick Method
- Measure room perimeter (add all wall lengths)
- Subtract doors and windows (roughly 10-15%)
- Divide by roll width (standard UK = 0.53m)
- This gives number of drops needed
- Divide roll length (10.05m) by your wall height to get drops per roll
- Add 1-2 extra rolls for pattern matching and repairs
Standard UK Wallpaper Roll
Most wallpaper in the UK comes in a standard size:
- Length: 10.05 metres (some European rolls are 10m exactly)
- Width: 0.53 metres (53cm)
- Coverage: 5.33 m² per roll (before pattern wastage)
Step-by-Step Calculation
1. Measure Room Perimeter
Add up the length of all walls you're papering. For a rectangular room: (length + width) × 2.
Example: 4m + 3m + 4m + 3m = 14m perimeter
2. Subtract Doors and Windows
Standard door opening = ~0.9m wide. Large window = ~1.5m. Subtract these from perimeter.
Example: 14m - 0.9m (door) - 1.5m (window) = 11.6m
3. Calculate Number of Drops
Divide adjusted perimeter by roll width (0.53m).
Example: 11.6m ÷ 0.53m = 21.9 → round to 22 drops
4. Calculate Drops Per Roll
Divide roll length (10.05m) by your wall height.
Example wall height 2.4m: 10.05m ÷ 2.4m = 4.18 → get 4 full drops per roll
5. Calculate Rolls Needed
Divide total drops by drops per roll.
Example: 22 drops ÷ 4 drops per roll = 5.5 → buy 6 rolls
Pattern Repeat
Patterned wallpaper has a repeat distance (printed on the label, e.g. "64cm repeat"). You must match the pattern across adjacent strips, which creates wastage.
How Pattern Repeat Affects Calculation
With a 64cm (0.64m) repeat and 2.4m wall height:
- First drop starts at top of pattern
- Second drop must align, so you cut at 2.4m + 0.64m = 3.04m from roll
- This means you waste the offcut between 2.4m and 3.04m (0.64m wasted)
For large repeats (50cm+), you may only get 3 full drops per roll instead of 4.
Drop Match vs Straight Match
- Straight match: Pattern lines up horizontally across strips. Less wastage.
- Drop match (offset match): Pattern repeats diagonally. Every other strip is offset. More wastage (buy 1-2 extra rolls).
Wallpaper Calculator Table
Quick reference for standard 2.4m ceiling height, plain paper (no pattern):
| Room Perimeter | Rolls Needed |
|---|---|
| 10m | 5 rolls |
| 12m | 6 rolls |
| 14m | 7 rolls |
| 16m | 8 rolls |
| 18m | 9 rolls |
| 20m | 10 rolls |
Add 1-2 rolls for pattern repeat over 30cm, or complex rooms with chimneys/alcoves.
Special Cases
Feature Wall
Only papering one wall? Measure just that wall's width and height. Calculate drops for that wall only.
Sloped Ceilings
Use the tallest wall height for your calculation. You'll waste more on the shorter side but avoid running short.
Chimney Breasts and Alcoves
Measure each section separately. Chimney breasts often need partial drops, so add an extra roll.
Always Buy Extra
Order at least one extra roll beyond your calculation:
- Batch matching (different batches vary slightly in colour)
- Mistakes during hanging (rips, misaligned patterns)
- Future repairs (discontinued patterns impossible to match)
Most suppliers accept returns of unopened rolls within 30 days.
Instant calculation: Use our wallpaper calculator for automatic results. Just enter room dimensions and pattern repeat.