Calculator for wallpaper

Decoration tips | Novembre 16

Before buying your wallpaper, you need to work out the number of rolls necessary for your room without any waste. The calculation depends on the wallpaper you choose. You do have to take into account a possible repeat which will have to be added to the height of the strips.

 1) Wallpaper with a repeat

If the wallpaper is plain or if the patterns do not have to match from one strip to another, you do not need to take the repeat into account.

If the wallpaper has a straight match (the patterns repeat themselves on a horizontal line) or a half drop (the patterns repeat one lay out of two), you need to add the length indicated on the roll label to the height which you have measured when calculating the strips (from the skirting board to the ceiling).

2) How to calculate the number of rolls you need

We suggest a simple calculation to work out the number of wallpaper rolls you need for yours walls:

  • Measure the room height as well as its perimeter (without the openings), divide the perimeter by the roll width (0.53 mostly), in order to find out the number of strips you will need.
  • Divide the roll length (10 metres mostly) by the wall height + 10 cm finishes + the possible repeat length in order to find out the number of strips per roll.
  • Round up always and plan to take an extra roll just in case.
  • If you need to cover window recesses, doors, archways or alcoves, please do not take them out of your calculation of the room perimeter except if these are very big. In that case, you only need to add the dimension of the recess to your calculation.


When you buy your wallpaper, please check carefully the batch number of each roll to avoid having tone differences in the same colour. In the case of plain wallcoverings, please check on the label if you have the symbol ↑↓ in order to follow this particular hanging instruction. Please think also of keeping the remains of rolls already opened…just in case you have an accident whilst hanging as you might not necessarily find the same pattern for small repairs.