Wallpaper Calculator
Wallpaper math is about strips, not square metres: a roll yields a fixed number of full-height strips, and pattern repeat can waste a quarter of every roll. This calculator does the strip arithmetic for you.
Enter the total width of the walls to be papered, the ceiling height, your roll size and the pattern repeat from the roll label.
Enter valid values to see the results.
Formula
Each strip needs the wall height plus pattern repeat (to align the design) plus ~10 cm (4 in) of trimming allowance. A standard 10.05 × 0.53 m roll covers a 2.6 m wall with 3 strips per roll when there is no repeat — only 2 with a large repeat.
How to measure
- Add up the widths of all walls to be papered (the room perimeter), minus only very large openings like patio doors.
- Measure ceiling height in several places and use the largest value.
- Find the pattern repeat on the roll label (a number in cm next to a repeat symbol) and choose the closest option.
Worked example
Practical tips
- Buy one extra roll beyond the calculation — mistakes, damaged corners and future repairs all draw from it.
- Check that all rolls share the same batch number; colours differ between print runs.
- Start hanging from the window and work away from the light so strip shadows do not show.
- For patterned paper, unroll and dry-match two strips before pasting to see the real repeat consumption.
Waste allowance
Waste is built into the strip calculation: pattern repeat and trimming are added to every strip. Add one spare roll instead of a percentage.
Strips per roll at 2.6 m (8.5 ft) ceiling
| Roll size | No repeat | Large repeat |
|---|---|---|
| Standard 10.05 × 0.53 m | 3 | 2 |
| Euro 10.05 × 0.70 m | 3 | 2 |
| Wide 25 × 1.06 m | 8 | 6 |
Common mistakes
- 1 Calculating by square metres instead of strips — a roll cannot be split across two walls efficiently.
- 2 Ignoring pattern repeat, which can increase roll count by 30–50%.
- 3 Measuring height once: floors and ceilings are rarely level, so use the largest measurement.
- 4 Forgetting that wide (1.06 m) rolls need two people to hang and different paste tables.
Frequently asked questions
How many rolls of wallpaper for a 4×4 m room?
Perimeter is 16 m. With standard 0.53 m rolls and 2.6 m ceilings: 31 strips, 3 per roll without pattern → 11 rolls; with a large repeat → 16 rolls.
How much wallpaper does one roll cover?
A standard 10.05 × 0.53 m roll covers about 5.3 m² on paper, but in practice 3 full strips at 2.6 m height — roughly 4 m² of wall. Pattern repeat reduces this further.
What is pattern repeat?
The vertical distance before the design repeats, printed on the label. Each strip must start at the same design point, so the repeat length is effectively wasted on every strip.
Should I deduct windows and doors?
Only very large openings (wider than one strip, floor-to-ceiling). Strips above and below windows still come from the roll, so small deductions are misleading.
Is it cheaper to paint or wallpaper?
Paint is usually 2–3 times cheaper in materials for the same wall area. Wallpaper wins on texture, pattern and hiding imperfect walls.