How the wallpaper roll calculator works
Required strips = ceiling(total wall width in inches ÷ roll width in inches). Effective drop length = ceiling((wall height × 12 + trimming allowance) ÷ pattern repeat) × repeat when a pattern repeat is specified; otherwise wall height × 12 + trim. Strips per roll = floor(roll length in inches ÷ effective drop length). Rolls = ceiling(required strips ÷ strips per roll).
Worked example
For a 32 ft wide wall run, 8 ft high, using 20.5 in × 33 ft rolls, a 12 in repeat and 4 in trimming: 19 strips are needed; each drop takes 108 in and each roll yields 3 strips, so estimate seven rolls.
Before you order
Pattern direction, half-drop matching, roll dye lots, obstacles, offcuts, and defective sections can change the final order. Confirm roll specifications.
All results are planning estimates, not a guarantee of installed material quantity or a quote. Measure the actual project, verify product labels, and follow the manufacturer’s instructions.
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