Follow these steps:

1. Measure the width and height of each wall.
2. Calculate each wall’s area by multiplying its width by its height.
3. Add the wall areas together, accounting for large openings where appropriate.
4. Check the wallpaper roll dimensions and pattern repeat.
5. Estimate the number of full-length drops each roll will provide.
6. Allow for pattern matching, cutting waste and any future repairs.

For example, a wall measuring 4 metres wide and 2.4 metres high has an area of 9.6 square metres. However, dividing that area by the roll’s stated coverage may underestimate the amount needed because wallpaper is installed in vertical lengths and patterns must align.

A professional installer can help with complex staircases, sloping ceilings, large murals and patterns with substantial repeats.