Wallpaper calculator
Find out how many rolls of wallpaper a room takes. The calculator counts by strips, the way a paperhanger does: it adds trimming, rounds each strip up to the pattern repeat and counts how many whole strips one roll gives.
You need
9 rolls
3 strips per roll · strip 2.70 m
- Strips around the room
- 25 strips
- Paste
- 2 packs
- Wall length without doors2 × (4.00 + 3.00) − 1 × 0.80 = 13.20 m
- Strip: height + 10 cm for trimming2.60 + 0.10 = 2.70 m
- Whole strips from one roll10.05 ÷ 2.70 → 3
- Strips around the room13.20 ÷ 0.53 → 25 strips
- Rolls25 ÷ 3 → 9 rolls
- Paste, one pack for 5 rolls9 ÷ 5 → 2 packs
Windows don't save strips: the wall above and under them is papered too.
The calculator gives an estimate by the usual norms. Consumption depends on the product and the surface: check the manufacturer’s data before you buy.
How it’s calculated
- 1
Wall length = perimeter of the room minus the doors (windows don’t save strips: the wall above and under them is papered too).
- 2
Strip length = wall height + trimming at the floor and the ceiling, rounded up to whole pattern repeats.
- 3
Strips per roll = roll length ÷ strip length, whole strips only.
- 4
Strips around the room = wall length ÷ roll width, rounded up.
- 5
Rolls = strips ÷ strips per roll, rounded up; paste by the number of rolls one pack covers.
Worked example
A 4 × 3 m room with 2.6 m ceilings and one door, plain wallpaper in standard 0.53 m rolls:
The input
- Length, m
- 4
- Width, m
- 3
- Height, m
- 2.6
- Doors
- 1
- Roll
- Standard roll 0.53 × 10.05 m
- Pattern repeat
- None
The result
9 rolls
3 strips per roll · strip 2.70 m
- Strips around the room: 25 strips
- Paste: 2 packs
The calculation
- Wall length without doors2 × (4.00 + 3.00) − 1 × 0.80 = 13.20 m
- Strip: height + 10 cm for trimming2.60 + 0.10 = 2.70 m
- Whole strips from one roll10.05 ÷ 2.70 → 3
- Strips around the room13.20 ÷ 0.53 → 25 strips
- Rolls25 ÷ 3 → 9 rolls
- Paste, one pack for 5 rolls9 ÷ 5 → 2 packs
How many rolls of wallpaper for a 4 × 3 room?
With 2.6 m ceilings and one door the walls run 13.2 m. Each strip is 2.7 m with trimming, so a 10.05 m roll gives 3 strips. The room takes 25 strips of a 0.53 m roll — 9 rolls; with wide 1.06 m rolls it is 13 strips, 5 rolls.
How does the pattern repeat change the count?
With a repeat, every strip must start at the same point of the pattern, so it is rounded up to whole repeats: with a 64 cm repeat a 2.7 m strip becomes 3.2 m. A roll may then give fewer strips — and the room more rolls. Check the repeat on the roll label.
Questions
Why aren’t windows subtracted?
Strips go over and under a window, and the pieces cut out there are rarely long enough for anything else. Counting by strips without the windows gives the real number of rolls.
How much trimming to add?
Usually 10 cm per strip — about 5 cm at the floor and 5 cm at the ceiling, for an even edge.
Should I buy a spare roll?
It is a good idea for patterned wallpaper and for rooms with many corners: a spare roll of the same batch saves a mismatch if a strip is spoiled.
The same calculator in the Kvadrino app
Kvadrino for Android works offline: enter the room once and get tiles, paint, flooring and an estimate for the client. The app is in closed testing — write to us and we will add you as a tester.
Coming soon to Google Play