How to calculate the number of rolls
First, calculate the area covered by one roll (width × length). Then divide the wall area (already including the waste margin) by the roll area.
Why the margin is higher than other materials
Patterned wallpaper needs "pattern matching" (aligning the design between strips), which creates more waste than flooring or paint — that's why the suggested default here is 15%, going up to 20-25% for large pattern repeats.
Standard roll size
A common wallpaper roll is 53 cm wide by 10 m long (~5.3 m²) — the defaults in this calculator, but always check the specific packaging.
Tip
For large pattern repeats (over 50 cm), consider increasing the waste margin to 20-25%.
Frequently asked questions
Why does wallpaper have more waste than paint?
Because patterns need to line up between strips ("pattern matching"), which creates bigger offcuts and leftovers.
What's the standard wallpaper roll size?
A common size is 53 cm wide by 10 m long, but sizes vary — always check the packaging.
Do I need a bigger margin for large patterns?
Yes, large pattern repeats (over 50 cm) usually require 20-25% waste, instead of the 15% default.
Does this calculator account for doors and windows?
Not automatically — for better accuracy, subtract large opening areas from the total wall area before calculating.