Wallpaper Calculator

How many rolls of wallpaper you need, worked out by drops: room size, wall height, roll size and pattern repeat (straight or half-drop match).

Wallpaper is hung in drops (full-height strips), so the number of rolls depends on how many drops you need and how many you can cut from each roll, not just on the wall area. A 4 × 3 m room is 14 m around; with standard 53 cm rolls that's 27 drops, or 25 once you leave out a door. With 2.4 m walls and 10 cm for trimming, each drop is 2.5 m, so a 10.05 m roll gives 4 drops and you need 7 rolls. A pattern repeat makes every drop longer: with a 53 cm repeat each drop becomes 2.65 m, only 3 fit on a roll, and the same room needs 9 rolls. This calculator works the same way for any room or wall, standard, wide or US double rolls, straight or half-drop matches, and leaves out the width of doors.

Units
Measure by
Room
ft
ft
ft
Feet and inches work too: type 12'6 or 12.5.
Doorways to leave out
ft
in
in
Rolls
8

20.5 in × 33 ft (double roll)

Drops
24

full-length strips

Wall length
41 ft

after doors

How it was worked out
  1. Walls: 2 × (12 + 10 ft) = 44 ft around × 8 ft high = 352 ft²
  2. Leave out 3 ft of wall for doors
  3. 24 drops of 8.33 ft (height + trim); 3 drops per 33 ft roll
  4. Rolls: 8 rolls

Windows aren't taken off, because the paper above and below them comes from full drops. Buy every roll from the same batch, and an extra roll for mistakes is worth having.

Common use cases

  • Order wallpaper for a bedroom, hallway or living room
  • Paper a single feature wall
  • See how much a large pattern repeat adds
  • Check rolls before ordering a batch, so you don't run short

How to use

  1. Enter the room's length, width and wall height, or switch to Wall for a feature wall.
  2. Enter any doors to leave out (windows are left in, as the paper around them comes from full drops).
  3. Choose your roll size and enter the pattern repeat from the label, and the match type if there is one.
  4. Read the rolls, the drops and how many drops each roll gives.

FAQ

How many rolls of wallpaper do I need?

Divide the length of wall by the roll width to get the drops, then divide the roll length by the drop length (wall height plus trim, rounded up to the pattern repeat) to get drops per roll. Rolls = drops ÷ drops per roll, rounded up. For a 4 × 3 m room 2.4 m high with standard rolls and no repeat, that's 7 rolls.

What size is a roll of wallpaper?

The standard roll in the UK and Europe is 10.05 m long and 53 cm wide, about 5.3 m². Wide rolls of about 1.06 m are also common. In the US wallpaper is often sold as double rolls of about 20.5 in × 33 ft (about 56 ft²). Check the label, as sizes vary.

What is a pattern repeat and a half-drop match?

The repeat is the distance before the pattern starts again down the roll. With a straight match the pattern lines up across drops at the same height; with a half-drop each drop is shifted by half a repeat, which wastes a little more. Larger repeats waste more paper per drop.

Should I buy an extra roll?

It's worth it. Rolls from a different batch can differ slightly in colour, so buy enough from one batch to cover mistakes and future repairs.

Related tools