Formula
How the wallpaper estimate works
- Net wall area = wall width × wall height − openings
- Cut length = wall height rounded up to the next pattern repeat
- Rolls required = strips needed ÷ usable strips per roll × (1 + waste %), rounded up
Free project planning tool
Wallpaper calculator
Estimate wallpaper strips and full rolls using wall size, roll dimensions, pattern repeat, openings, and waste.
✓ Metric & imperial✓ Transparent assumptions✓ No signup
Rolls & pattern repeatInstant estimate
Example calculation
A 24 × 8 ft wall with 20 sq ft of openings, 20.5 in wide wallpaper, a 33 ft roll, and a 21 in pattern repeat needs about five full rolls with a 10% allowance.
Planning tips
- Use the roll’s printed width, length, and vertical pattern repeat.
- Large repeats and half-drop matches can increase waste substantially.
- Order all rolls from the same dye lot when color matching matters.
Common questions
Wallpaper calculator FAQ
Why does pattern repeat increase the roll count?
Each strip must be cut long enough for the pattern to align, leaving an unusable portion at the end of some drops.
Should I subtract windows and doors?
You can subtract large openings, but keep enough allowance for matching, trimming, and strips above or below openings.
Does this support double rolls?
Yes. Enter the total width and length printed on the product, whether the package is described as a single, double, or euro roll.