Wall width + strips + rolls
Wallpaper Calculator
Find how many rolls you need for an accent wall or room. Account for your chosen roll size, trimming, and straight pattern repeat before you buy.
Example only
- 20.5 in wide
- 8 strips
- 33 ft long
- 3 strips / roll
- Pattern
- No repeat
Based on 4 in trimming per strip. Use your product’s dimensions below.
How it works
Count usable strips, then whole rolls
Wallpaper comes off the roll in full-height strips. Count each wall separately at corners; roll area alone can hide offcuts left after trimming and matching a design.
Example: a 12 ft wide, 8 ft high accent wall
- 12 ft × 12 ÷ 20.5 in roll width = 7.02, so plan 8 full-height strips.
- Each strip needs 8 ft × 12 + 4 in trimming = 100 in.
- A 33 ft roll gives floor(396 ÷ 100) = 3 strips.
- 8 strips ÷ 3 per roll = 2.67, so buy 3 rolls before optional spares.
For a straight match, the cut length rounds up to the next full vertical repeat. Verify your selected product’s match type and package length.
Before ordering
Use the specifications on your roll
Measure the wall
For a rectangular room, use the length and width to find its perimeter. Measure the full wall height.
Check the label
Roll width, roll length, pattern repeat, and match type vary. A quoted square-foot coverage is not the roll length.
Buy one dye lot
Add any spare rolls you want, and check the dye lot or run number before purchasing.
FAQ
Wallpaper calculator questions
How many rolls of wallpaper do I need?
Divide each wall width by the roll width and round up to full-height strips before adding the walls together. Then divide the roll length by the cut length of one strip to find how many strips fit on each roll. Round up to whole rolls.
Does the calculator allow for pattern repeat?
Yes, for a straight-across match. Enter the vertical repeat printed on the product label. Each cut length rounds up to a whole repeat after trimming allowance. Check half-drop and other offset patterns with the manufacturer.
Should I subtract doors and windows?
This tool counts full-height strips across the measured wall width. It does not assume offcuts around doors and windows will supply another usable strip. A full-height opening may reduce the strip count; check your layout before buying.
What is a double roll or bolt?
Some wallpaper is sold as a double roll or bolt even when listings use the word roll. Enter the actual width and total length of the package you will buy, then treat the result as that package count.
Can I use this for peel-and-stick wallpaper?
Yes, if the product comes in continuous rolls. Enter its real width, length, and repeat. For precut panels or murals, follow the product-specific layout instructions instead.
References
Sources behind this calculator
Product specifications and installation instructions take priority over a general estimate.
Roll sizes and dye lots
York’s guide describes double-roll packaging, typical dimensions, and matching dye lots.
York Wallcoverings guide ↗Pattern match types
The Wallcoverings Association explains random, straight-across, and half-drop matches.
Wallcoverings Association ↗Trimming and buying
The Wallcoverings Association’s installation guide adds 4 in to a wall measurement before cutting a strip.
Wallcoverings installation guide ↗More tools