how to calculate rolls

Our instructions on how to calculate wallpaper quantities will prevent you from running out and reduce waste. Please refer to below as this is how we estimate the amount of rolls require. However, the best way to ensure you have the right amount of rolls would be to check with a professional installer.

Here's our step-by-step guide:

Before you begin...
Make sure you know the width of your chosen wallpaper, the length of the roll, and the pattern repeat (if the wallpaper has one).

Below calculations are based on roll size 53cm x 10m with pattern repeat of 38cm.

1. Measure the wall
First, you will need to measure each wall that you want to paper. Measure the width and the height in centimetres. If the walls have the same heights you can add the widths together, if not you will need to work out one wall at a time.

Example:
Wall (A) 150cm width x 220cm height
Wall (B) 180cm width x 220cm height
Wall (C) 110cm width x 180cm height

This instance works out two wall spaces. There's walls (A) and (B) 330cm x 220cm, and wall (C) 110 cm x 180cm.

2. Get dividing
You can now divide your wall widths by your wallpaper width to work out how many drops you need.

Example:
Wall (A & B) 330cm / 53cm = 6.22. Always round up = 7 drops
Wall (C) 110cm / 53cm = 2.07 round up = 3 drops

3. Multiply
Next you will need to multiply the number of drops by the wall height.

Wall (A&B): 7 drops x 220cm height = 1540cm
Wall (C): 3 drops x 180cm height = 540cm

*If you are using wallpaper that has no vertical pattern repeat, you can skip to number 5.

However if you have a wallpaper with a pattern repeat, there is still a little more work to do!

4. Pattern repeat
To work out the pattern repeat allowance, you need to add a pattern repeat for each drop, apart from the first one.

Example:
7 + 3 drops = 10
10 drops – 1 = 9 pattern repeats
9 x 38cm pattern repeat = 342cm

*If your design has an offset match (half drop) then you need to add half of your total pattern repeat again.

For example: 342cm / 2 = 171cm
342cm + 171cm = 513cm

5. Add your totals together
Add your totals together which will tell you the total meterage you require to cover your walls. Divide this by the roll length to work out how many rolls you need.

Example:
1540cm + 540cm + 342cm = 2422cm
2422cm / 1000cm (10 metres) = 2.422. You can’t buy part rolls, so round this up to 3 rolls.