MihsabaHow to use
Calculate net wall area and whole wallpaper rolls after subtracting openings and adding waste using your roll coverage.
- Enter Wall area (m²).
- Enter Openings area (m²).
- Enter Coverage per roll (m²).
- Enter Waste (%).
- Calculate, then review the assumptions before purchasing.
How it is calculated
Example
A 60 m² wall area with 8 m² of openings leaves 52 m². At 10% waste and 5.2 m² per roll, 11 rolls are required.
Important notes
Usable roll coverage can fall when patterns must match or many cuts are required. Use coverage appropriate to the wallpaper and pattern, not only the theoretical roll area.
Worked examples and interpreting results
A 60 m² wall area with 8 m² of openings leaves 52 m². At 10% waste and 5.2 m² per roll, 11 rolls are required.
| Case | Calculation | Result |
|---|---|---|
| Net area | 60 − 8 | 52 m² |
| Rolls required | ceil(52 × 1.10 ÷ 5.2) | 11 |
How to check the result
Usable roll coverage can fall when patterns must match or many cuts are required. Use coverage appropriate to the wallpaper and pattern, not only the theoretical roll area.
Frequently asked questions
Should doors and windows be subtracted?
They can be subtracted when their area is known, but repeating patterns may still justify an additional allowance.
Should I include waste?
Include an allowance when cuts, breakage or layout losses are expected. Use a percentage that fits your project rather than assuming one fixed rate.
Do the units need to match?
Yes. The calculator assumes the units stated beside each field, so convert measurements first when your source uses different units.