Wallpaper Calculator
Wall, opening, and roll estimator
Enter wall measurements and wallpaper roll details
Result
Calculation summary
Enter values to see the result
Wallpaper strip preview
Room wallpaper coverage
How to use this calculator
- 1Choose a whole room, a single wall, or multiple walls and enter the measured dimensions.
- 2Add doors, windows, or custom openings that will not be covered.
- 3Enter the wallpaper roll dimensions, pattern repeat, and waste allowance, then calculate the whole rolls required.
Formula
Rolls = ceil(required strips ÷ floor(roll length ÷ pattern-adjusted drop length))
Wall widths determine the strip count. The tallest wall and pattern repeat determine each cut length; openings reduce complete strip equivalents, waste increases the strip count, and rolls are rounded up.
Calculation steps
- Validate wall, opening, roll, repeat, unit, and waste inputs.
- Convert dimensions to meters and calculate gross and net wall area.
- Divide each wall width by roll width and round up to complete strips.
- Round the tallest wall height up to the next pattern repeat to get the cut length.
- Apply opening deductions and waste, calculate strips per roll, and round up to whole rolls.
Worked example
A 5 m × 4 m room with 2.8 m walls uses 36 gross strips with 0.53 m wide wallpaper. With no pattern repeat, 10 m rolls provide 3 strips each; adding 10% waste requires 40 strips, or 14 rolls.
Assumptions
- Rooms are rectangular and use a uniform wall height.
- Wallpaper is installed as vertical strips and roll dimensions come from the product label.
- Openings reduce only complete strip equivalents, giving a conservative estimate for partial offcuts.
- For mixed wall heights, all strips use the tallest wall and its pattern-adjusted cut length.
- Pattern matching is treated as a straight repeat; offset, drop, motif placement, defects, and installer-specific layout may require more material.
Sources
Frequently asked questions
Where do I find the wallpaper roll size and pattern repeat?
Use the roll width, roll length, and repeat printed on the wallpaper label or technical sheet. Products and markets use different roll formats.
What should I enter for wallpaper without a repeating pattern?
Enter zero for pattern repeat. The calculator will use the tallest wall height as the strip cut length.
Why are doors and windows converted to complete strips?
A wall opening does not always eliminate a full vertical drop. Counting only complete strip equivalents avoids assuming every offcut can be reused.
Does the calculator support drop-match patterns?
This version models a straight pattern repeat. Add extra waste or follow the manufacturer layout guidance for half-drop, offset, or large-motif designs.
Can leftover strips from one wall be used on another?
Possibly, but this depends on wall heights, pattern alignment, corners, defects, and cut locations. The estimate uses the tallest wall for a conservative project-level roll count.