How this calculator works
The model assumes equal-height walls and straight pattern matching. Each wall’s width is rounded to full strips, and each drop includes trim before being rounded up to the pattern repeat. Half-drop matches, complicated corners and mixed wall heights require a manual layout.
The formula
Matched drop = ceiling((height + trim)/repeat) × repeat, or height + trim for plain paper. Rolls = ceiling(required drops × allowance / full drops per roll).A quick example
Four 4 m walls at 2.4 m height need 32 strips of 0.53 m width. With 0.1 m trim and no pattern repeat, each 10 m roll provides four 2.5 m drops: eight rolls.
How to use this calculator
- Choose the settings that match your scenario, using the units shown beside each field.
- Enter width of each wall, wall height, number of equal walls, roll width.
- Calculate, then review the method and assumptions alongside the results.
A few common questions
Why can an area-only estimate be too low?
Roll offcuts may be too short for another full-height drop, even though their combined area appears sufficient.
Are doors deducted?
No. Openings can still require full strips for pattern continuity. Review the hanging layout before reducing quantities.