How Many Rolls of Wallpaper Do You Need? How to Calculate

The number of rolls is found by dividing the total width of the walls by the roll width, and the roll length by the strip length. Dividing the area in square metres is misleading, because the short leftover pieces on a roll usually cannot be used.

Roll calculation in four steps

1. Add up the widths of the walls to be papered.
2. Divide this total by the roll width and round up: the number of strips.
3. Add 10 cm trimming allowance to the ceiling height, plus the repeat for patterned paper: the strip length.
4. Divide the roll length by the strip length and round down: strips per roll. Divide the number of strips by this and round up.

Worked example

A room with a 15 m perimeter and a 2.70 m ceiling, with rolls of 0.53 × 10.05 m: 15 ÷ 0.53 = 28.3, so 29 strips. The strip length is 2.80 m and each roll gives 3 strips. 29 ÷ 3 = 9.7, so you need 10 rolls. With rolls of 1.06 × 10.05 m the same room takes 15 strips and 5 rolls.

Common mistakes

• Deducting doors and windows: the offcuts from those areas do not fit anywhere else.
• Forgetting the repeat: with a large pattern you can get one strip fewer per roll.
• Buying no spare: the same batch number is hard to find later, so buy one extra roll.

How do you calculate rolls for a ceiling?

The method is the same: the side the strips run along becomes the strip length, and the other side is divided by the roll width. On ceilings the strips are usually hung parallel to the light from the window.

Enter your measurements in the wallpaper calculator to see the result straight away. In Bahçeşehir, Beylikdüzü and Başakşehir, Erdağ Yapı takes the measurements on site during a free survey.