Wallpaper calculator
Wallpaper roll
calculator
Calculate wallpaper rolls for one to four walls using your roll size and pattern repeat. Doors and windows are deducted, matching waste is included, and the selected colour and texture appear in 3D.
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Based on your result
What you'll need
Quantities update after every calculation. Always buy every roll from the same batch so the colour matches across the wall.
- Wallpaper
- Rolls including pattern repeat and waste
- Calculate above
- Wallpaper paste
- Adhesive to hang every roll
- —
- Smoothing tools
- Brush, seam roller and sponge
- 1 set
- Trimming knife
- A sharp blade for clean edges
- 1 tool
The maths
How we work out your wallpaper
We work in full-height strips rather than area, because that is how wallpaper actually hangs. The pattern repeat rounds each drop up so the design lines up, then we count how many strips each wall needs and how many strips you get from one roll — and turn that into whole rolls with waste added.
strips = Σ ⌈ wall width ÷ roll width ⌉
strips / roll = ⌊ roll length ÷ drop ⌋
rolls = ⌈ strips × waste ÷ strips per roll ⌉
- 10–20%
- waste (you choose)
- repeat
- lengthens each drop
- full drops
- kept over openings
- 1 pack
- paste per 5 rolls
- same batch
- for colour match
- ft ↔ m
- converted automatically
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01
Measure the walls
Enter each wall you are papering and the room height — the strips are counted wall by wall.
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02
Match the pattern
The repeat rounds every drop up to the next full pattern, so seams line up across the room.
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03
Count the strips
Each wall’s width is divided by the roll width to give the number of full-height strips it needs.
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04
Fit strips to a roll
Roll length divided by the drop tells us how many usable strips come out of one roll.
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05
Add waste and round up
Strips are padded 10–20% and divided by strips-per-roll, then rounded up to whole rolls.
Good to know
Wallpaper questions, answered
To line up a design, every strip has to start at the same point in the pattern, so each drop is rounded up to the next full repeat. A large repeat wastes more at the top of every strip, which is why a bold pattern needs more rolls than a plain paper of the same size.
A drop is one full-height strip of wallpaper, cut to the room height plus enough to match the pattern and trim top and bottom. The number of drops you get from a roll depends on the roll length divided by that drop length.
Usually only a little. You still hang full drops across a wall and cut around the opening, and the offcut above or below a door rarely yields another usable full strip. We keep full drops so the pattern stays matched, which is the safe approach.
As a rule of thumb, one tub covers about five rolls, so the calculator rounds up on that basis. Paste-the-wall papers can use a little more; always check the specific paper’s instructions, as some come pre-pasted and need none.
It is wise. Buying one spare from the same batch means you can repair a scuff or damaged strip years later without a visible colour difference — dye lots vary between print runs, so matching later is difficult.
A standard North American roll is about 20.5 inches wide and 33 feet long; a European roll is roughly 53 cm by 10 m. Use the figures printed on your chosen paper — width and length both change how many strips you get.
Yes. Switch to metres and the wall dimensions and roll length convert automatically, while roll width and pattern repeat stay in the units printed on the roll. Results are shown for your chosen system.