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 need. This guide will explain how to do precisely that. We’ll ask questions like;

- How many drops are in a roll of wallpaper?
- How wide is the roll?
- How much does one roll cover?

By answering these questions and more, you’ll be able to do all the calculations necessary to determine how much wallpaper you need to buy.

## Calculating the Number of Drops in a Roll of Wallpaper

### 1. Measure the Walls

Start by taking a tape measure and measuring the width and height of the wall you want to cover.

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.

### 2. Check the Length of the Wallpaper

There will be measurements in the manufacturer’s sample book and wallpaper packaging. Find out how long the roll is. Finding the length is essential for wallpapers that are a non-standard size.

### 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 often you could drop a roll of paper from the ceiling to the floor (or skirting board), cut it off and drop it 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 at the edges. The margin is only a few inches for small prints, like polka dots. 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.

### 4. Check the Width of the Wallpaper

You know where to look, on the packaging or sample book.

### 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!

### 6. Multiply Step 5 by Step 3

The number of rolls needed to cover the width multiplied by the number of drops equals the 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.

### 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 when you 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 it for all other walls if they need covering too.

Here’s a handy online calculator that I find useful: www.cole-and-son.com/en/faq/roll-calculator. You 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, which will be noticeable when the paper is up.

## How Many Drops are in a Roll of Wallpaper? – Final Thoughts

So that’s how to calculate how much wallpaper you need. Remember, when in doubt, check with the manufacturer or store.

BTW, if you’re planning on wallpapering a feature wall, make sure you read this guide: ‘How to Wallpaper a Feature Wall‘.