Q: How do I know how much wallpaper I need?

A: To calculate the amount you will need first work out the number of drops you will need (width of your wall divided by the width of the wallpaper).  You may have to round the number up.  You then multiply this number of drops by the height of the wall and you get the metres needed for your wall excluding the wallpaper pattern repeat.  Multiply your wallpaper pattern repeat by the number of drops needed minus 1.   Add this figure to the metres needed without pattern repeat and this gives you the final amount of metres for covering your wall.  Divide this by the number of metres on a roll to give you the final number of rolls needed.

Example

Wall width is 348cm, wall height is 266cm

Wallpaper roll is 52cm wide with a 76.2cm pattern repeat and the roll is 10m long.

348/52 = 6.69 (rounded up to 7 = 7 drops)

7 drops x 266cm wall height = 1,862cm

76.2cm pattern repeat x 6 (7 drops - 1) = 457.2

457cm + 1,862cm = 2,319.20cm = 23.19 metres

23.19 metres divided by 10 metres on a roll = 2.31 rolls

Therefore you will need 3 rolls of wallpaper