How can I calculate how many rolls of wallpaper I need?

Dear Francois,
Several factors need to be taken in consideration when calculating how many rolls of wallpaper you need to order for your decorating project:

1. The size of the wallpaper roll
   Most wallpapers are sold in rolls. The European standard format is 0.53 × 10.05 metres (21 inches × 33 feet). As many other formats and sizes exist on the market, always check the exact size specifications of the wallpaper you are purchasing.
2. Width and height of the wall
   You need to measure the width of each wall you are planning to wallpaper. If your wall has different heights always measure up to the highest point. Don’t worry about doors and windows, just calculate the entire surface of the wall.
3. The type of pattern repeat on your chosen wallpaper
   The type of pattern on the wallpaper will determine how much wallpaper will have to be cut off for the pattern to match from strip to strip and therefore how many rolls you will need.

If there is no pattern, a random pattern or a pattern of vertical stripes (free match) you will be able to cut each length with almost no cut-offs.

If the patterns are at the same height for all lengths of wallpaper (straight match) the wasted cut-offs will be at a minimal level.

If your wallpaper pattern has an offset match, only every other length will look the same and there will be more cut-offs.

This information is always provided in the wallpaper specifications.

How do I use an online calculator to determine how many rolls I require?

Many online wallpaper shops provide roll calculators on their websites that will help you to find out how many rolls you need. You just enter your wall measurements and the calculator will take the pattern repeat of your wallpaper into consideration and give you the exact number of rolls you need to buy for your project. Avoid generic calculators and use instead the one provided on the page of the wallpaper model you want to buy. It is already pre-configured with the correct wallpaper measurements, reducing the risk of mistakes.

How can I manually calculate how many rolls of wallpaper I need?

You don’t trust online calculators, or simply want to double-check the result? Just follow these simple steps, provided in both metric and imperial measurements:

For those using the metric system
scroll down for Imperial

How many strips of wallpaper will I need?

Let’s assume our wall is 5.00 m wide and that our wallpaper is a standard 0.53m × 10.05 m. What we need to do is to divide the wall width by the wallpaper width:

5.00 m (wall width) / 0.53 m (wallpaper width) = 9.43 (number of strips needed)

As we always need to round it up, we know we need 10 strips for our project.

How many strips are provided on a wallpaper roll?

OK, next step: assuming our wall is 2.80 m high and the pattern repeat is 0.72 m, let’s first find out the number of recurring patterns in each strip:

2.80 m (wall height) / 0.72 m (pattern repeat) = 3.88 (number of patterns)

Rounded up, we know that the number of recurring patterns is 4.
Time to calculate how long each strip is going to be:

4 patterns × 0.72 m (pattern repeat) = 2.88 m (length of the strip)

Now we can find out how many strips we can cut from one roll:

10.05 m (roll length) / 2.88 m (length of each strip) = 3.49 strips

So, from each roll we can cut 3 full strips.

How many rolls do I need to buy?

As we know we need 10 strips for our project, the final calculation is quite easy:

10 (number of strips needed) / 3 (number of strips per roll) = 3.33 rolls

Since you can’t buy less than a roll and you always need to add about 15-20% to account for any waste, let’s round it up to the next roll. In the above example you will need 4 rolls.

You can simply replace the numbers in the example above with your own to calculate your total.

For those using the imperial/US customary system

How many strips of wallpaper will I need?

Let’s assume our wall is 16 ft (192 in) wide and that our wallpaper is a standard 21 in × 33 ft. What we need to do is to divide the wall width by the wallpaper width:

192 in (wall width) / 21 in (wallpaper width) = 9.14 (number of strips needed)

As we always need to round it up, we know we need 10 strips for our project.

How many strips are provided on a wallpaper roll?

OK, next step: assuming our room is 9.17 ft (110 in) high and the pattern repeat is 28.35 in, let’s first find out the number of recurring patterns in each strip:

110 in (wall height) / 28.35 in (pattern repeat) = 3.88 (number of patterns)

Rounded up, we know that the number of recurring patterns is 4.
Time to calculate how long each strip is going to be:

4 patterns × 28.35 in (pattern repeat) = 113.4 in (9.45 ft) (length of the strip)

Now we can find out how many strips we can cut from one roll:

33 ft (roll length) / 9.45 ft (length of each strip) = 3.49 strips

So, from each roll we can cut 3 full strips.

How many rolls do I need to buy?

As we know we need 10 strips for our project, the final calculation is quite easy:

10 (number of strips needed) / 3 (number of strips per roll) = 3.33 rolls

Since you can’t buy less than a roll and you always need to add about 15-20% to account for any waste, let’s round it up to the next roll. In the above example you will need 4 rolls.

You can simply replace the numbers in the example above with your own to calculate your total.

Remember: Always round up your calculations and add some extra. It’s better to have too much wallpaper than too little. The last thing you want is to have to stop your decorating project because you didn’t buy enough!

Your wallpaper expert
Isabel