How to calculate the amount of wallpaper I will need?

The correct calculation of the amount of wallpaper you will need for your interior is a key issue. If you are purchasing it at the specialised store, the amount needed will be calculated for you by the professionals. But you want to be sure that you buy the correct amount also when shopping online.

In that case, you will need a helper – the following formula:

(width of the wall + repeat) x height wall = X m²

Round up the result up to a whole number
Standard wallpaper rolls made n Europe have dimensions of 10.05 m x 0.53 m, which amounts to 5 m² (square meters).
Calculation still continues – dividing the surface area of the wall (X) by the surface of the wallpaper roll:

X ÷ 5 = Y

Round up Y to whole number and you have the required number of rolls.
All operations must  be calculated in the same units, ideally in meters.

By "repeat"  we mean a number that can be found on the label of wallpaper rolls as "repeat" or "rapport." It indicates the length or the interval after which the wallpaper pattern repeats. This interval must be respected and individual wallpaper strips fitted together for seamless continuation of the pattern.

The calculation can then be checked as follows: If the height of your walls is between 2.70 and 2.80 m, you can be sure that the roll of wallpaper sized 10.05 x 0.53 cm will be enough for 3 strips. Thus covering 159 cm in width. And what is the total width of your wall? The number of rolls is now easy to calculate.

For example

The width of the wall is 3.40 m and height 2.80 m.
Repeat of the wallpaper pattern is 0.2 m
(3.45 + 0.2) x 2.8 = 10.22 m² / round up to 11
11 ÷ 5 = 2,2 /  round up to 3
You will need 3 rolls of wallpaper.