How to Work Out How Much Wallpaper or Paint You Need

Patterned wallpaper

Decorating your home is a great way of changing the interior, stamping your own design and creativity ideas onto it and improving the look and style of a property.

But before you start slapping on the paint or gluing up the wallpaper, you need to know how much wallpaper or paint you actually need to complete decorating a room.

Here’s a guide to working out these all important calculations!

When you’re painting or wallpapering a room, it’s important to ensure you have enough materials for the job before you start.

It’s frustrating running short of anything and, with wallpaper in particular, can cause problems, as sometimes there are slight colour differences between different rolls of wallpaper.

As you don’t want your newly papered walls to be mismatched, it’s important to have enough wallpaper to complete the job from the outset.

Whilst not buying enough materials is a hassle, buying too much isn’t. Any unopened tins of paint or rolls of wallpaper can easily be returned to the store in their original condition for a refund.

They won’t want to accept back partly used tins of paint or wallpaper rolls, but these are always useful to keep in case you need to touch-up any walls at a later date or decide to paint or paper another room in the same colour or design.

Calculating How Much Paint or Wallpaper You Need to Buy

In order to correctly work out how much paint or wallpaper you need to buy to decorate a room of your home you have to apply some simple mathematical calculations.

Arm yourself with a tape measure, steel ruler, pen and paper. If you’re using a tape measure, you may benefit from someone else helping, with the aim of keeping the tape measure in place!

Don’t try and measure the entire room in one go. Instead, break it down into smaller manageable sections, such as one wall at a time.

Don’t’ forget to factor in areas above windows or doors too, plus the ceiling if you are painting it.

Choose which measurement you’re going to use – either metres or feet – and stick to it; mixing types of measurements will always end in confusion.

Measure the height of each area of the wall and the width of it. If you multiply these two measurements together you will get the total area measurement for this section.

Do the same for all the walls in the room, then add the figures together and you’ll have the total area of the entire room.

On average, one litre of paint can provide a single paint cover for approximately 14 square metres or 150 square feet.

The amount of wallpaper included on each roll varies, so you’ll need to check how much is included on the wallpaper you’re using.

To find the amount of paint you need, divide the paintable area by 150 square feet (or 14 square metres – the amount of paint in each one litre tin).

In the case of wallpaper, you’ll need to divide the area that you’ll be wallpapering by the amount of wallpaper on each roll.

If you’re not a fan of maths, don’t panic! There are a few cheat ways of doing this too, as many large online DIY stores provide a free calculator tool on their websites.

All you need to know are the room size dimensions and relevant websites and they do all the hard work of calculating the result for you.

Other Useful Tips

If you are planning on painting over wood chip walls or textured wallpaper, then it may require slightly more paint. Allow about one third more to cover this.

If you’re painting a light coloured paint over an existing dark paint, then you may well need slightly more paint to get a good colour. For example, it may need two or three coats of paint to achieve the desired effect.

If you have any old or leftover pale paint from previous decorating, you could use this as an undercoat for painting over a dark room.

It will act as a good base layer for painting your new colour onto and will help save you a bit of money with buying lots of new paint.

See Also
Green painted living room
Combining Colours
Floral wallpaper
Choosing and Hanging Wallpaper