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Blank walls are boring, so it’s fashionable to liven them up by papering them in a bold print.
However, wallpaper has a reputation for being difficult to apply. Even before you start wrestling with paste and paper, you must work out how much wallpaper you will need. This guide will explain how to do precisely that. We’ll ask questions like;
- How many drops in a roll of wallpaper?
- How wide is the roll?
- How big an area will one roll cover?
By answering these questions and more, you’ll be able to do all the calculations necessary to work out how much wallpaper you need to buy.
Step 1: Measure The Walls
Start off by taking a tape measure and measuring the width and the height of the area you want to cover. This area might be one wall, for a feature, or all the walls in a room, in which case you need to add the widths of each wall together.
Unless you have a window that is essentially a wall of glass, don’t bother taking away space for doors and windows. This extra space will ensure you have enough spare wallpaper.
Step 2: Check The Length Of The Wallpaper
In both the manufacturer’s sample book and on the wallpaper packaging, there will be measurements. Find out how long the roll is. Finding the length is especially important for wallpapers that are a non-standard size.
Step 3: Divide The Height Of The Walls By The Length Of The Wallpaper
When you have completed this calculation, you will have the number of ‘drops’ on the roll. The term ‘drops’ refers to how many times you could drop the roll of paper from the ceiling to the floor (or skirting board), cut it off and drop again before the roll runs out.
The number of drops is affected by the pattern repeat margin, which is written on the packaging/in the sample book.
Wallpaper lengths must pattern match on the edges. For small prints, like polka dots, the margin is only a few inches. However, for bold prints (e.g. life-size tropical birds that are currently in vogue – see image above), the pattern repeat margin will be much higher, and you will need more rolls.
For wallpaper with a complicated pattern, it’s best to ask a sales assistant for help with calculations. When in doubt, always go by the manufacturer’s guidelines.
Step 4: Check The Width Of The Wallpaper
You know where to look by now, on the packaging or in the sample book.
Step 5: Divide The Length (Horizontal) Of The Walls By The Width Of The Wallpaper
This calculation gives you the number of rolls it will take to cover the width of the walls. We’re nearly there!
Step 6: Multiply Step 5 Figure By Step 3 Figure
The number of rolls needed to cover the width multiplied by the number of drops = Number of rolls required. If you have a decimalised number, always round up, so 2.1 becomes 3 rolls, 4.6 becomes 5 rolls and so on.
Step 7: Add On An Extra Roll
Always add on an extra roll. There is nothing worse than wallpapering most of a room, only to run out of paper and find out that the shop you bought it from has sold out.
Most stores will allow you to return unused rolls but check at the time of purchase.
Example Calculation For One Wall Only
- Roll width = 53cm
- Roll length = 10 metres (1,000cm)
- Wall width = 450cm
- Wall height = 240cm
240 (wall height) divided by 1,000 (roll length) = 0.24
450 (wall width) divided by 53 (roll width) = 8.49
8.49 x 0.24 = 2.04
Round up = 3
Add an extra roll = 4 rolls to buy
Remember that the calculation above is just for one wall, so repeat for all other walls if they need covering too.
BTW, here’s a handy online calculator that I find useful: www.cole-and-son.com/en/faq/roll-calculator. You simply type in your measurements and off you go!
Pro Tip: House Beautiful recommends checking the batch number on each roll of wallpaper is the same. There are slight differences in dye lots in different batches, and this will be noticeable when the paper is up.
So that’s how to calculate how much wallpaper you need to buy. Remember, when in doubt, check with the manufacturer or store.
If you’re planning on wallpapering a feature wall, make sure you read this guide first: ‘Wallpapering Feature Walls – How The Professionals Do It’.
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