Enter dimensions
ConstructionHow to calculate the number of wallpaper rolls
The calculation is based on the room's perimeter (to determine the number of vertical strips) and ceiling height (to determine the length of each strip). Knowing the roll dimensions, you can calculate how many strips come from one roll, and from there, the total number of rolls needed.
Why pattern repeat (rapport) matters
If the wallpaper has a distinct repeating pattern, adjacent strips need to be hung with the pattern matched. This means part of each new piece is "lost" aligning the pattern with the previous strip, so the actual usable strip length is shorter than the physical roll length. The larger the pattern repeat, the more waste.
Practical tips
- Buy extra: it's recommended to add 1-2 extra rolls beyond the calculation for cutting mistakes or future repairs.
- Check the batch number: all rolls should be from the same production batch (listed on the label), otherwise there may be a noticeable shade difference.
- Account for pattern direction: some wallpaper has a direction (up/down), which also affects cutting and waste amount.
This calculation is an estimate. For complex rooms with alcoves, protrusions, or irregular shapes, consulting a professional or wallpaper store advisor is recommended.
FAQ
Why does pattern repeat (rapport) matter?
Wallpaper with a large pattern requires matching the design between strips, so part of each new piece becomes waste — this increases the total quantity needed.
Should I subtract the area of doors and windows?
For a more precise calculation — yes, especially in smaller rooms with large windows. However, many calculators recommend a small buffer for cases where openings aren't accounted for.
Should I buy wallpaper from a single production batch?
Yes, always check the batch number on the label — rolls from different batches can have a slight color shade difference.