Order enough wallpaper for a room

The job

Wallpaper is sold by the roll, but rooms are measured by the wall. The conversion from linear meters to rolls depends on roll width and length, ceiling height, and whether the pattern must be aligned across strips.

Measure and compute

Enter the room length and width, ceiling height, the roll's width and length, and the pattern repeat if the paper has one. Add openings to subtract and a waste allowance. The result is the number of strips, drops per roll, and total rolls.

• Pattern repeat matters: a 64 cm repeat can waste almost a full drop per roll compared to a plain paper.
• Doors and windows are usually left in unless they are very large — installers match pattern over them anyway.

Worked example

A 4 m × 3 m room at 2.4 m height has a 14 m perimeter. With 53 cm rolls, that is 27 strips; a 10.05 m roll gives 4 drops, so 7 rolls before allowance — 8 with 15% extra.

Where it stops

It estimates strips and rolls only — it does not account for sloped ceilings, stairwell walls, or matching half-drop patterns. Inputs are capped at 100 × 100 m rooms, 6 m wall height, 3 m roll width and 100 m roll length. Always round up to whole rolls at the store.