Wallpapering a room is one of the easiest and most cost-effective ways to makeover a space. With so many beautiful styles on the market, choosing a design is the easy bit. This wallpaper calculator intends to help you choose just how much you need for a particular room, and to de-mystify some of that wallpaper jargon, such as 'pattern matching', 'pattern repeat', 'paste the wall' and so on! We will also teach you how to measure for wallpaper so that you know exactly how many rolls of wallpaper will be required to complete your space.


How many rolls of wallpaper should I buy?

Now you've chosen a wallpaper design, we'll show you a basic calculation to determine how many rolls of wallpaper you should buy. This is by no means the only method to calculate the number of rolls required, but it is a technique tried and tested by our interior designers for when they calculate wallpaper quantity for their clients. Note - use consistent units throughout the calculation i.e. either cm or m. Do a single calculation for each wall you are papering to find out the number of rolls required and then add each number of rolls required per wall together. 

  1. First, measure the width and height of the wall requiring wallpaper.
  2. Next, find out the number of drops required. To do this, divide the width of the wall by the width of the wallpaper (usually 52cm) and round up to the nearest whole number.
  3. Then, find out the length of each drop. To do this, take the height of the wall, add 30cm for wastage and an additional 10% for any pattern repeat and/ or pattern match.
  4. Almost there - next find out how many drops can be achieved per roll. Do this by dividing a roll length (usually 1000cm) by the length of each drop (step 3).
  5. Finally! To find out the number of rolls required for the wall, divide the number of drops required by the number of drops per roll and round up to the nearest whole number.

Wallpaper Calculator Example...

  1. Wallpapering a wall measuring 400cm x 250cm (width x height) 
  2. 400cm/ 52cm = 7.69 = 8 drops required
  3. (250cm + 30cm) +10% = 308cm drop length
  4. 1000cm/ 308cm = 3 drops per roll
  5. 8 drops are required, therefore 8/3 = 2.6 rolls = 3 rolls required

Different types of wallpaper

Understanding the different types of wallpaper will ensure you select a paper suitable for the job, with each wallpaper stating recommended cleaning and durability.  It is, for example, obvious to use more durable, hardwearing wallpaper in a busy hallway, than a rarely used guest bedroom! For bathrooms and utility areas, the best type of wallpaper to use is vinyl, but no wallpaper is recommended to come into direct contact with water.


Wallpaper Application Methods

‘Paste the wall’

Just as it sounds, where the paste is directly applied to the wall before the wallpaper is hung. This is a much quicker method of hanging wallpaper, but it is not available for traditional papers as these expand when wet so must be left to soak before hanging.

'Paste the paper' 

The application method whereby the paste is applied to the reverse of the wallpaper before hanging. This method involves a process called “booking” which refers to the activation of the paste that occurs whilst the paper is resting before hanging the strip. 

Please refer to the individual wallpaper for the application type.

Wallpaper Terminology

When calculating the wallpaper quantity, if you have selected a patterned paper it is important to understand that pattern repeat and pattern matching are two different things:

Vertical Pattern Repeat (PR)

One complete pattern repeat is the distance of one full repeat of the design; it is identified on each roll of the wallpaper

Pattern Matching

Some patterns do not run straight horizontally; therefore sometimes pattern matching needs to be taken into account when calculating how much wallpaper to buy (step 3 in the wallpaper calculator).

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Types of Wallpaper Pattern Matching

Straight Match

Patterns match on adjoining drops, no wallpaper lengths are required.

Random or Free Match

Patterns match no matter how drops are positioned next to each other (eg a striped pattern), no additional length required.

Reverse Hang Alternative Lengths

Used for a striped wallpaper to ensure visual effects such as shading aren’t apparent, no additional length required.

Drop Match

Written on the wallpaper roll as either a quarter, half, a third or three-quarter drop match. For example, a three-quarter drop pattern repeat requires three-quarters of the pattern repeat to be included in every even numbered drop.

Offset Match

Written on the wallpaper roll: ie 26cm, this means the point the wallpaper drops match from left to right is every 26cm therefore an additional 26cm needs to be included for every even numbered drop.


Tips from the designers!

  1. Always read the instructions first, they do vary for different wallpapers!
  2. Lining paper (cross lining/ horizontally hung) is a great idea to hide poor quality walls, lumps and bumps.
  3. If using a dark coloured paper, painting the wall the same colour behind the joins and/or colouring the end of the paper with a toning water based felt tip pen will avoid unsightly lines.
  4. It’s helpful to pencil the hanging order on the reverse of each wallpaper drop to be hung before starting to avoid confusion.
  5. Always use a high quality adhesive; all wallpaper brands supply them, so you know it will work perfectly with the same branded wallpapers.
  6. The alternative to wallpaper is paint! Find our top tips on how to paint your home here.

Please note that the information provided in this wallpaper calculator is correct to the best of our knowledge and experience, no liability whatsoever can be accepted on the basis of the information supplied herein.