Home improvement
Wallpaper Calculator
Works wallpaper quantity, where the pattern repeat drives the waste.
Result
Pattern repeat drives waste more than anything else. A large repeat can waste nearly a third of every roll, because each drop must be cut to align with the last.
Get a Free Business AuditHow the calculation works
Wall height plus the pattern repeat allowance gives the drop length, from which the drops per roll follows, and the perimeter divided by the roll width gives the drops needed. The pattern repeat is the sensitive input, since matching the pattern at each drop wastes a length up to the repeat on every single one.
What moves the number
- Pattern repeat length.
- Whether the match is straight or offset.
- Wall height and roll dimensions.
- Number of drops, which the perimeter determines.
Where this one goes wrong
A large pattern repeat can waste a substantial share of every roll, because each drop has to start at the right point in the pattern and the offcut is too short to use elsewhere, which means a bold pattern costs considerably more than a plain paper of the same price. Allow for it properly. Ordering from the same batch matters as much as in flooring, since colour varies between production runs and a mid-wall change of batch is visible.
Before you quote
- Add the pattern repeat to the drop length.
- Check whether the match is straight or offset.
- Order all rolls from the same batch.
Questions
About this calculator
Why does patterned wallpaper need more rolls?
Because each drop has to start at the right point in the pattern, so a length up to the repeat is wasted on every drop and the offcut is too short to use. A bold pattern costs considerably more than a plain paper of the same price.
What is an offset match?
A pattern where adjacent drops are hung with a vertical offset rather than level, which changes the waste calculation and the hanging sequence. The roll label states which match applies, and it affects the quantity needed.
Does the batch matter?
Yes. Colour varies between production runs, and a change of batch part way along a wall is visible. Ordering all the rolls together from the same batch, with a spare, avoids a mismatch that cannot be corrected afterwards.
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How to use this calculator
- Total wall length (ft) (ft). Enter your own figure; the page starts at 44 ft.
- Wall height (ft) (ft). Enter your own figure; the page starts at 9 ft.
- Coverage per roll (sq ft) (sq ft). Enter your own figure; the page starts at 56 sq ft.
- Waste allowance (%). 15% for a small repeat, up to 30% for a large one.
- Cost per roll ($). Enter your own figure; the page starts at $48.
- Doors and windows (sq ft) (sq ft). Enter your own figure; the page starts at 42 sq ft.
The result updates as you type, so you can try a figure, see what it does to rolls needed, and change it back. Nothing you enter is sent anywhere or saved.
A worked example
These are the figures the calculator opens with. Every number in the results column below is produced by the same calculation the page runs, so you can follow it through before putting your own figures in.
What goes in
| Input | Value |
|---|---|
| Total wall length (ft) | 44 ft |
| Wall height (ft) | 9 ft |
| Coverage per roll (sq ft) | 56 sq ft |
| Waste allowance | 15% |
| Cost per roll | $48 |
| Doors and windows (sq ft) | 42 sq ft |
What comes out
| Result | Value |
|---|---|
| Rolls needed main result | 8 |
| Area | 354.0 |
| Area including waste | 407.1 |
| Estimated material cost | $384 |
For 354.0 sq ft plus 15% waste you need 8 rolls, costing about $384.
How sensitive the answer is
Holding everything else steady and changing only cost per roll, this is what happens to rolls needed. It is worth knowing which of your inputs the answer actually hinges on, and which barely move it.
| Cost per roll ($) | Rolls needed |
|---|---|
| $24 | 8 |
| $36 | 8 |
| $48 example above | 8 |
| $72 | 8 |
| $96 | 8 |
Every other input is held at the example value while this one changes, which is not how a real job behaves. Treat it as a guide to which number matters most, not as five separate quotes.
What each figure means
- Total wall length (ft) (ft)
- Measured in ft, starting at 44 ft.
- Wall height (ft) (ft)
- Measured in ft, starting at 9 ft.
- Coverage per roll (sq ft) (sq ft)
- Measured in sq ft, starting at 56 sq ft.
- Waste allowance (%)
- 15% for a small repeat, up to 30% for a large one.
- Cost per roll ($)
- A money amount, starting at $48.
- Doors and windows (sq ft) (sq ft)
- Measured in sq ft, starting at 42 sq ft.
What the results tell you
| Result | What it is |
|---|---|
| Rolls needed | The headline result. A number. |
| Area | A decimal figure. |
| Area including waste | A decimal figure. |
| Estimated material cost | A money figure. |
Keep going
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