Wallpaper calculator
We count the usable drops per roll, not just the area.
Your inputs
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Example loaded. You can change any value.
There is no figure yet: nothing is calculated until you ask for it.
- Enter your measurements.
- Check the units and the assumptions.
- Press Calculate, or load the example.
Rather see a worked case? Press “Load example” and change any value afterwards.
Next step
Ceilings are almost never papered: they get painted, and that is a different area.
Where each number comes from Conversion constants are exact; densities and coverage rates come from cited sources; everything else is an assumption you can change. Methodology · Sources and updates
How to use it
- Add up the length of every wall you are papering: that is the perimeter.
- Measure the wall height, from skirting to ceiling.
- Enter the roll size: the European standard is 53 cm x 10.05 m.
- If the paper has a matching pattern, enter the repeat in centimetres.
How it is calculated
Wallpaper is not calculated by area, it is calculated in drops. A 10 metre roll does not give you 10 usable metres: it gives a whole number of drops the height of your wall, and whatever is left at the end is scrap.
Here is the trap that leaves people short: with an 8 ft 2 in wall and a 10.05 m roll you get 3 drops, not 4. Each drop needs about 4 inches spare to trim top and bottom, and 4 x 2.6 m = 10.4 m, more than the roll holds.
Doors and windows are not subtracted. The offcuts above a door rarely fit anywhere else, so deducting them would leave you short.
Worked example
A room with a 46 ft perimeter, 8 ft walls, standard 53 cm x 10.05 m rolls, plain paper:
- Drop length: 2.44 + 0.1 = 2.54 m
- Drops per roll: 10.05 / 2.54 = 3.95 → 3 drops
- Drops needed: 14.02 / 0.53 = 26.5, plus 10 % waste → 30 drops
- Rolls: 30 / 3 = 10 rolls
If the wall were 7 ft 6 in, the drop would be 2.39 m and you would get 4 per roll: 8 rolls instead of 10. Six inches of height cost two rolls.
Good to know
- Pattern repeat costs paper. With a 64 cm repeat, each drop can need up to 64 cm extra to match. That is often one roll more in every three.
- Buy one batch. The batch number is printed on wallpaper for a reason: shade differences between batches are visible on the wall.
- High ceilings change everything. Above 2.6 m, almost no standard roll yields more than three drops.
- Keep a spare roll. Replacing one damaged section without a matching roll means redoing the whole wall.
Frequently asked questions
How many rolls of wallpaper do I need?
For a room with a 46 ft perimeter and 8 ft walls in plain paper, about 10 standard European rolls. The number depends heavily on height: at 7 ft 6 in you would need 8, because you get four drops per roll instead of three.
How many drops do you get from one roll?
Divide the roll length by the wall height plus about 10 cm of trim, then round down. A 10.05 m roll gives 4 drops up to a 2.4 m wall, and only 3 from 2.45 m upwards.
Are doors and windows subtracted?
No, and that is deliberate. The pieces left above a door or below a window are rarely reusable, so deducting them would leave you short of paper.
What is a pattern repeat and why does it matter?
It is the vertical distance at which the design repeats. To match the pattern between drops you waste up to that distance on each drop. Large repeats can add 20-30 % to the paper needed.
What size is a standard wallpaper roll?
In Europe, 53 cm wide by 10.05 m long. American rolls are wider and sold by the single, double or triple roll, so enter the real dimensions of what you are buying.