Work out how many rolls of wallpaper you need for a room.
Calculated instantly in your browser.
How do you calculate how many rolls of wallpaper you need?
Drops per roll = roll length ÷ (wall height + repeat); Strips needed = wall width ÷ roll width; Rolls = strips (plus waste) ÷ drops per roll, rounded up. Each drop is one floor-to-ceiling strip, and a pattern repeat adds length so the design lines up. A 12 m run, 2.4 m high, with 10.05 m × 0.53 m rolls and 10% waste needs about 7 rolls.
Understanding your result
Each “drop” is one floor-to-ceiling strip. A pattern repeat adds length to every drop so the design lines up. Always buy whole rolls from the same batch for a consistent colour.
Formula and method
Drops per roll = roll length ÷ (wall height + repeat). Strips needed = wall width ÷ roll width. Rolls = strips (plus waste) ÷ drops per roll, rounded up.
Assumptions and limitations
The count comes from the wall and roll dimensions and the repeat you enter, and assumes rectangular walls. Large pattern repeats, alcoves, sloping ceilings and many openings change the real total, so add waste and round up to whole rolls. It does not plan paste, lining paper or how strips fall around windows and doors.
Worked example
A 12 m wall run, 2.4 m high, with 10.05 m × 0.53 m rolls and 10% waste needs about 7 rolls.
How to use this tool
- Choose metres or feet and enter the total wall width and height.
- Enter the roll length, roll width and any pattern repeat.
- Set a waste allowance, then press Calculate.
About the Wallpaper Calculator
The Wallpaper Calculator works out how many rolls you need to cover a room, allowing for the pattern repeat and a waste margin.
Who should use this tool
Homeowners and decorators papering a room who want a roll count that allows for the pattern repeat and waste. Useful for feature walls and whole rooms, and for checking how many rolls to buy from a single batch before ordering.
Benefits
- Works out rolls needed for a room or wall
- Allows for the pattern repeat on every drop
- Adds a waste margin so you buy enough
- Free in the browser, no sign-up required
Practical use cases
- Estimating rolls for a whole room
- Papering a single feature wall with a repeat
- Allowing for a pattern repeat when ordering
- Buying enough rolls from one batch
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Frequently asked questions
Should I buy an extra roll?
Yes — keeping a spare roll from the same batch is wise for repairs later, since dye lots vary between batches.
How does the pattern repeat affect how much I need?
A repeat means each drop must be cut longer so the design lines up with the next strip, and that extra length is wasted at the top or bottom. The bigger the repeat, the more you lose per drop, which is why patterned papers usually need more rolls than plain ones.
What is a drop in wallpapering?
A drop is a single floor-to-ceiling strip of paper. The number of drops a roll yields depends on your wall height plus the pattern repeat, and how many drops you need depends on the wall's width divided by the roll width. The tool combines these to give a roll count.