Wondering: “How much wallpaper do I need?” Measuring how much wallpaper you need is easier than you think. Whether it’s one feature wall or the whole room, working it out properly means less waste and less stress.
Our guide on how to calculate wallpaper takes you through a few simple steps. Plus, the wallpaper calculators on our product pages do all the hard work for you.
Caroline Woolmer, our Head of Product Design at I Love Wallpaper, also shares her top tips for avoiding common wallpaper measuring mistakes.
Contents
- How to use our wallpaper roll calculators
- How to measure for wallpaper: Step-by-step
- Common wallpaper mistakes and how to prevent them
- Frequently asked questions
How to use our wallpaper roll calculators
Our wallpaper calculators on each I Love Wallpaper product page help you figure out exactly how many rolls you’ll need for your space. Simply head to the product you love, enter your wall measurements, and we’ll take care of the rest.
Using a wallpaper calculator tailored to the product you’re buying is always better than using a one-size-fits-all tool. It takes into account the unique aspects of your wallpaper, like pattern repeat, ensuring you get just the right amount for a flawless result.
How to measure for wallpaper: Step-by-step
While our wallpaper calculators on our product pages do the hard work for you, you’ll still need to measure your walls and subtract any large doors or windows before popping the numbers into the tool.
Every space is unique, but by following these steps, you’ll be confident in your measurements and ready to order the right amount of wallpaper.
What you’ll need:
-
A metal tape measure
-
A notepad or phone to jot measurements down
-
A calculator (or just use our product-specific wallpaper calculators for ease)
Method:
1. Measure the width and height of each wall
Start by measuring the width of each wall you plan to wallpaper in metres. Take your tape measure from one corner to the other, going all the way across. And don’t forget to include any alcoves or recesses you want to cover.
Next, measure the height of the wall, from the top of the skirting board up to the ceiling. If you have a vaulted ceiling or it isn’t level, take the measurement at the highest point.
2. Multiply the width and height of each wall
Once you have both width and height for each wall, multiply them together to get the total square metres for each. For example, if a wall is 4 metres wide and 2.5 metres high, that wall covers 10 square metres.
Write down each wall’s square metre measurement and then add them all together to get the total area you need to cover.
3. Subtract space for large windows and doors
Once you’ve calculated the total wall area, it’s time to subtract the parts you won’t be wallpapering, like windows and doors. This helps avoid over-ordering and keeps your measurements as accurate as possible.
To do this, measure the height and width of each window or door in metres, just like you did for the walls. Then, multiply those measurements together to find the area of each.
For example, if you have a door that’s 2.1 metres high and 0.9 metres wide: 2.1 × 0.9 = 1.89 square metres.
Let’s say you also have a large window that’s 1.5 metres high and 1.8 metres wide: 1.5 × 1.8 = 2.7 square metres.
Add those together: 1.89 + 2.7 = 4.59 square metres.
Now subtract that total from your full wall area. So, if your walls added up to 30 square metres and you’re subtracting 4.59 square metres for openings: 30 − 4.59 = 25.41 square metres. That’s the actual area you’ll be covering with wallpaper.
You don’t need to subtract small windows, alcoves, or things like fireplaces, as it’s always better to have a little extra, especially when matching patterns or trimming edges. A small overestimate is far more helpful than coming up short mid-project.
4. Work out how many rolls you need
Check the roll coverage of your chosen wallpaper, which is usually stated on the product page. Most wallpaper rolls cover around 5.2 square metres, but this can vary depending on the brand or design.
Divide your total wall area by the coverage per roll to find out how many rolls to order. For example, if the total area of your walls (after subtracting windows and doors) is 25.41 square metres, and the wallpaper you’ve chosen has a roll coverage of 5.3 square metres, you would divide the total area by the roll coverage: 25.41 ÷ 5.3 = 4.79.
Since you can’t order a fraction of a roll, always round up to the nearest whole number. So, in this case, you’d order 5 rolls.
5. Account for pattern repeat
If your wallpaper has a pattern — like florals, geometrics, damask, or tropical prints — it's important to factor in something called the pattern repeat when calculating how many rolls to order.
Pattern repeat is the vertical distance from one part of the pattern to where it repeats again further down the roll. So if you spot a flower at the top of the roll and see the same flower again 50cm down, the repeat is 50cm. This comes into play when hanging your wallpaper, as each strip needs to start in just the right place so the design lines up with the one next to it.
To get that perfect match, you'll need to cut each strip slightly longer than your wall height. That extra bit allows you to align the pattern, but it also means you'll use more wallpaper overall.
The amount of extra wallpaper you’ll need depends mainly on the repeat length in centimetres. The longer the repeat, the more you'll need to allow. The type of pattern match also plays a role:
-
Straight match — The pattern aligns straight across each strip, so you just match each one at the same height. You'll still need to add one full repeat to your wall height to allow for trimming. For example, if your wall is 240cm high and the pattern repeat is 50cm, each strip should be: 240 + 50 = 290cm long.
-
Offset or half drop — The pattern shifts by half a repeat on each strip, which creates a staggered, flowing look. These usually need 1.5 times the pattern repeat added to your wall height. For example, if your wall is 240cm high and the repeat is 50cm, you'd allow: 240 + (50 × 1.5) = 315cm per strip.
-
Free match (or no match) — There's no need to line up the pattern, so you can cut each strip exactly to your wall height.
You’ll find the pattern repeat listed on each of our wallpaper product pages, so you’ll know exactly what to allow for.
Once you know how long each strip needs to be (including the repeat), divide the roll length by your strip length to see how many full strips you’ll get from one roll. Then, divide your total wall width by the roll width to find out how many strips you’ll need. From there, you can work out how many rolls to order. Just divide the number of strips needed by how many fit in each roll, and always round up to be safe — it’s better to have extra paper than less.
And if you'd rather skip the maths? The wallpaper calculators on each of our wallpaper product pages do it all for you, taking into account pattern repeat, so you can order with confidence. Just select the wallpaper design you love — whether it’s metallic, striped, or something else — and head over to the product page to input your measurements.
Common wallpaper mistakes and how to prevent them
We’re all about empowering decorating with ease, and that includes sidestepping a few common pitfalls.
1. Guesswork
Caroline says: “One of the biggest mistakes I see is guesswork — just guessing measurements or assuming you’ll have enough wallpaper without really doing the math. It might sound obvious, but taking the time to measure properly is the key to a smooth wallpapering experience. Trust me, spending a few extra minutes measuring your walls saves hours of stress later on. Our wallpaper calculators make it super easy to get it right. Just go to the product page, add your wall measurements, and it does the heavy lifting for you!”
2. Forgetting about doors and windows
“Forgetting to account for doors and windows is another classic mistake,” says Caroline. “It’s tempting to just measure the whole wall and call it done, but subtracting those spaces means you’ll order the right amount of rolls and won’t waste unnecessary money.”
3. Not accounting for pattern repeat
Caroline suggests: “Don’t underestimate the importance of the pattern repeat. If your wallpaper has a design, like florals or geometrics, you need to factor in how the pattern lines up. Overlooking this means you could end up with misaligned prints or running out of wallpaper because you didn’t allow for extra trimming. It’s a detail that makes a big difference to the final look.”
4. Underordering
“Underordering is always a nightmare. It’s really frustrating to get halfway through and realise you don’t have enough,” says Caroline. “Always order a little extra to cover pattern matching, trimming, and any unexpected mistakes. I usually recommend rounding up to the next roll, even if it feels like you’re buying more than you need. That way, you’re covered for any last-minute fixes or touch-ups.”
5. Not double-checking measurements
Caroline explains: “There’s a golden rule I always stick to: measure twice, maybe even three times, especially around tricky spots like windows and doors. Double-checking saves you from ordering too little or too much.”
Frequently asked questions
Should I measure for wallpaper in centimetres or metres?
Either works, but most wallpaper calculations are easier in metres since roll sizes and coverage are usually listed that way. Just make sure you’re consistent and convert everything before doing the math.
How wide is a roll of wallpaper?
Most wallpaper rolls are about 53 centimetres wide, which is just over half a metre. This width is pretty standard and works well for most walls and rooms. Just be sure to check the product page for the exact width before you buy, as some designs might vary slightly.
How many strips (drops) do you get from one roll?
“That depends on two things,” explains Caroline. “The length of your wallpaper roll (usually 10 metres) and how long each strip needs to be, which includes your wall height, plus any extra for pattern matching.”
“For example, if your strips need to be 2.93 metres long, you’d divide 10 metres by 2.93, which means you’ll get about 3 full strips per roll. This helps you figure out how many rolls to buy so you’ve got enough to cover your walls.”
Can I wallpaper a wall with uneven ceilings or sloping walls?
Absolutely! Just measure the highest point of the wall for your strip length to ensure you have enough wallpaper for the tallest part.
Can I use leftover wallpaper from a previous project?
You can try, but keep in mind that different batches of wallpaper can vary slightly in colour or pattern. It’s best to buy all you need upfront or double-check that leftover rolls match the new wallpaper exactly.
Shop wallpaper now at I Love Wallpaper
Now you know how to calculate for wallpaper, it’s time to pick the perfect design to transform your space.
We’ve got everything from bold florals and striking geometrics to more minimalist looks like wood panels and soothing neutrals. Plus, a whole range of paint colours to help you create your dream room.
Give it a go yourself with our how to hang wallpaper guide. Or if you’re tackling an old wallcovering, we’ve got all the best tips on how to remove wallpaper without stress.
Check out our blog for more expert tips and inspiration. Or contact us today — we’re always happy to answer any questions.
