About this Wallpaper
Wallpapering adds style and character to a room, but calculating rolls can be tricky due to pattern repeats and waste. This calculator determines the number of standard rolls you need to cover your walls.
Who this calculator is for
- Homeowners planning an accent wall or full-room wallpaper project.
- Decorators estimating roll counts before ordering wallpaper from a specific batch.
- DIY installers comparing different roll widths and lengths on a room layout.
When to use it
- Estimate wallpaper rolls from total wall width, height, and roll size.
- Account for a built-in waste factor for trimming and normal pattern matching.
- Compare whether a different roll width reduces the total roll count.
How to use this calculator
- Enter the Width and Height of the wall(s) you are covering.
- Enter the Roll Width and Roll Length (check product label).
- The calculator estimates the Rolls Needed.
Key assumptions
- Wall width is the combined width of the walls being covered, measured in feet.
- Roll width is entered in inches, roll length is entered in feet, and all dimensions must be positive.
- The calculator applies a fixed 15% waste factor and does not model custom pattern repeats or special layout tricks.
Accuracy and testing
Review formula sources, default test cases, assumptions, unit handling, rounding rules, and changelog for this calculator.
How this calculator works
1. Wall Area = Wall Width × Wall Height.
2. Roll Area = Roll Width × Roll Length.
3. Usable Area = Roll Area × 0.85 (assuming 15% waste for matching patterns/trim).
4. Rolls = Wall Area / Usable Area.
Inputs explained
Wall Dimensions
Measure the total width of all walls combined if doing a whole room.
Roll Dimensions
Standard US rolls are often 21" or 27" wide. European rolls are often 53cm (21").
Understanding your results
The result is rounded up to the nearest whole roll. Always buy all rolls from the same batch number to ensure colors match perfectly.
Example scenarios
Accent Wall
12ft x 9ft wall (108 sq ft). Standard roll (21" x 33' = ~57 sq ft). Usable ~48 sq ft. Needs 3 rolls.
Key Features
- Waste Factor Logic
- Custom Roll Sizes
- Area Coverage
Tips & Best Practices
- If you have a large pattern repeat (e.g., 24 inches), you will have more waste. Buy an extra roll.
- Do not subtract doors and windows unless they are very large. The waste from cutouts is usually needed for pattern matching.
Glossary of Terms
- Pattern Repeat
- The vertical distance between where the design is identical again.
- Double Roll
- Wallpaper is often priced by the single roll but sold in double rolls. Check the packaging carefully.