Wallpaper Calculator
Calculate how many rolls of wallpaper you need for a room, accounting for pattern repeat, doors, windows, and waste.
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Rolls Needed
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Net Wall Area —
Total Strips —
How to Use This Calculator
- Enter the room perimeter (or length + width × 2) and ceiling height.
- Enter the number of doors and windows to subtract.
- Enter the roll width, roll length, and pattern repeat in inches.
Formula
Strips per roll = floor(Roll length ÷ (Ceiling height + repeat))
Strip width ≈ roll width | Rolls = ceil(Total strips ÷ Strips per roll)
Example
Example: 52 ft perimeter, 9 ft ceiling, 24 in repeat, 20.5 in wide × 33 ft roll → 14 rolls.
Frequently Asked Questions
- Divide the total wall area by the usable square footage per roll, then add 10–15% for waste and pattern matching.
- A pattern repeat is the vertical distance before the pattern repeats. Larger repeats waste more wallpaper due to matching.
- A standard single roll is about 27 sq ft; a double roll is 54 sq ft. American rolls vary — check the label.
- For a 12-inch repeat, add about 10%; for a 24-inch repeat, add 15–20%. The calculator uses the pattern repeat to adjust drops per strip.
- Some installers wallpaper over openings and trim around them — in that case, do not subtract them. If you will not paper over them, subtract the openings.