How to measure for wallpaper
Measure each wall separately, at its widest point. Measure the height in several places and use the greatest height for this calculator. Enter only the walls you plan to paper.
Read the label first
Enter the width and length of the physical roll you receive. A US product may be priced by the single roll but supplied as a double roll. Do not enter the pricing unit as the physical length.
A worked example
A 4 m wide wall at 2.4 m high needs 8 strips of 0.53 m wide paper. With 0.10 m total trimming, each free-match cut is 2.50 m. A 10.05 m roll yields 4 strips, so 2 rolls cover the wall. One optional spare roll makes the order 3.
Doors, windows and corners
We keep openings in the gross wall width: full strips are often needed above and below them. This is conservative. Do not subtract opening area from a strip-based estimate. A professional cutting plan can reuse offcuts. Allow for corner overlaps and uneven walls when measuring.