Wallpaper Calculator
Estimate wallpaper rolls, full-height drops, pattern-repeat adjustment, wall area and material cost after door and window deductions.
Default project preview
10 rolls
Net wall area
381 ft²
Drops needed
29
Drops per roll
3
Adjusted drop
8.75 ft
Calculator
Build the material order
Your order will appear here
Enter the project details and calculate a rounded material estimate.
Input and output guide
What each value means
The labels and units below are part of this calculator’s visible methodology. Replace every default with measurements or product data from the actual project.
Room length
Enter this project assumption in ft. The current imperial default is 15 ft.
Room width
Enter this project assumption in ft. The current imperial default is 12 ft.
Wall height
Enter this project assumption in ft. The current imperial default is 8 ft.
Door and window area
Enter this project assumption in ft². The current imperial default is 51 ft². Minimum: 0.
Roll width
Enter this project assumption in in. The current imperial default is 20.5 in.
Roll length
Enter this project assumption in ft. The current imperial default is 33 ft.
Pattern repeat
Enter this project assumption in in. The current imperial default is 21 in. Minimum: 0.
Extra allowance
Enter this project assumption in %. The current imperial default is 10 %. Minimum: 0. Maximum: 50.
Price per roll
Enter this project assumption in a unitless value. The current imperial default is 48. Minimum: 0.
How to read the outputs
Net wall area
after openings. Default preview: 381 ft².
Drops needed
pattern-adjusted strips. Default preview: 29.
Drops per roll
from entered roll length. Default preview: 3.
Adjusted drop
pattern repeat included. Default preview: 8.75 ft.
Opening deduction
doors and windows. Default preview: 51 ft².
Material cost
full wallpaper rolls. Default preview: $480.00.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Net wall area = perimeter × height − openings. Pattern-adjusted drop = height rounded up to the next repeat. Rolls = round up (required drops ÷ drops per roll).
Reviewed project guidance
How to use this estimate in a real project
Last reviewed: July 29, 2026
Use this calculator to estimate wallpaper rolls from wall dimensions, openings, roll size and pattern repeat. It accounts for full drops, which is more reliable than dividing total area by roll area.
Calculation steps
- 1Measure total wall width to be covered.
- 2Divide by usable paper width to find drops.
- 3Increase drop length to the next pattern repeat.
- 4Determine drops per roll and round rolls upward.
Worked numerical example
A room perimeter of 54 ft with 8 ft walls and 21 in-wide wallpaper needs about 31 drops. If an 11 yd roll yields three pattern-matched drops, order 11 rolls before spare allowance.
Purchasing and rounding
Wallpaper is purchased by full rolls or double rolls. Order the same dye lot and retain one unopened roll when possible for repairs.
Interpret the result
Pattern repeat can reduce the number of usable drops per roll even though nominal roll area is unchanged.
Page-specific assumptions
- Vertical full-height drops.
- Consistent wall height.
- Pattern repeat and roll dimensions are correct.
- Openings are treated according to the chosen takeoff method.
Common mistakes
- Using roll area alone.
- Ignoring pattern repeat.
- Mixing single-roll and double-roll labels.
- Ordering different dye lots.
Primary and technical references
BuildMeter provides planning estimates, not engineering, architectural, electrical, mechanical, plumbing, permit or code approval. Review the methodology and verify final decisions with product documentation and qualified professionals.
BuildMeter Guides
Understand the measurements and assumptions
Use these visible reference guides before changing project inputs or planning allowances.
FAQ
Wallpaper Calculator questions
Why does pattern repeat increase roll quantity?+
Each strip may need extra length so the pattern aligns with the previous strip.
Should all openings be deducted?+
Large openings can be deducted, but small areas above doors and around windows still require cut pieces.
What is a double roll?+
Wallpaper packaging terminology differs by market. Always enter the actual width and total roll length printed on the product.