How many tiles do you need for your next DIY project? The golden rule experts use to always buy the perfect amount

Calculating how many tiles you need can be daunting – but not after reading this easy guide

Wallpapered kitchen with a tiled panel
(Image credit: Future PLC/David Giles)

If you’ve ever had to tile (or have tiled) your bathroom or kitchen floor, you’ll know that ordering the tile amount that’s just right - not too little and not too much - is a daunting task. How can anyone ever tell how many tiles one needs?

Well, it turns out that if you want to find out how to tile a kitchen splashback or even anything bigger than that, you need to go straight to the source – the tile experts. Because to them, it’s as easy as. And in fact, once the pros’ golden rule was imparted to us, the formula does seem pretty fool-proof.

So if you have a tiling project coming up, then this simple guide to how many tiles you should be ordering will surely come in handy.

Earthernware Cotto & Off White

(Image credit: Ca' Pietra)

How many tiles do you need?

So what is this famous formula? This golden rule experts swear by to correctly tile a wall or the floor (or both), you might ask.

‘There is a simple method that, if followed, will give you the right amount,’ says Grazzie Wilson, head of creative at Ca’ Pietra. ‘You need to measure the space, whether that is the floor or walls to give you the exact measurements.’

Marlborough Diamond & Silk Screen Lantau Bamboo Incardine

(Image credit: Ca' Pietra)

She continues, ‘For floors, measure the width and multiply it by the depth. For walls, measure the width of each wall and multiply it by the height. Repeat for each wall you're tiling and simply add the measurements together to calculate your total area.’

Abbas Youssefi, managing director of independent tile specialists Porcelain Superstore, adds a tip, ‘Always work in centimetres. Inches and feet are allowed of course, but you’ll find that most tile shops and tilers prefer to work in the decimal system.’

Wallpapered kitchen with a tiled panel

(Image credit: Future PLC/Paul Raeside)

Should you order extra tiles?

Yes, you should order extra tiles to account for any breakages or off-cuts when realising your bathroom tile ideas.

‘When ordering tiles, we recommend adding 10% wastage to the total square metres required – this is to allow for any wastage from cutting and installation,’ says Isabel Fernandez from Quorn Stone. ‘Ordering 10% wastage is an industry standard recommendation but you may want to consider ordering 15% or 20% wastage for smaller spaces or areas with more intricate cuts needed, for example, around a bathroom suite or shower alcove. This is because the wastage through cutting will be greater in proportion to the size of the area being tiled.’

Silk Screen Willow Cottage Smoke Green & VS Floor Finchley Forest Green

(Image credit: Ca' Pietra)

What to do about walls with windows and doors?

Obviously, you don’t want to be tiling over your windows if tiling a bathroom wall. So this needs to be accounted for when calculating how many tiles you’ll need.

‘Walls are generally rectangular shaped but sometimes they have windows or doors on them that need to be accounted for. So, what we need to do is first calculate the area of the entire wall, then subtract the area of the window or door that’s also on the wall,’ Abbas says.

Our favourite tiles to include in home projects


How many tiles per m2?

‘How many tiles you need per square metre entirely depends on the size of the tile – for example, you will need more tiles per square metre for a 600 x 400mm tile, compared to a 900 x 600mm tile,’ says Isabel Fernandez from Quorn Stone. ‘Most tile companies have a quantity calculator online to help you know how many square metres to how many tiles you will need.’

A kitchen with a tiled splashback and an artwork

(Image credit: Future PLC/Joanna Henderson)

Is it worth keeping extra tiles?

It is absolutely worth keeping a few extra tiles as a backup in case some break in the future.

‘Be sure to keep some spare tiles one finished,’ says Grazzie Wilson, head of creative at Ca’ Pietra. ‘Tiles are often made in batches and while every batch should look the same, there might be an ever so slight variation in colour. If any of your tiles get chipped or damaged, you’ll want to repair them and for them to match exactly. Plus, there is always the risk your tiles may get discontinued and you don’t want that.’

And that’s all you need to know about calculating how many tiles you need for a tiling job. It’s much easier than it seems, right?

News Writer

Sara Hesikova has been Ideal Home’s News Writer since July 2023, bringing the Ideal Home’s readership breaking news stories from the world of home decor and interiors, as well as trend-led pieces, shopping round-ups and more. Graduating from London College of Fashion with a bachelor’s degree in fashion journalism in 2016, she got her start in niche fashion and lifestyle magazines like Glass and Alvar as a writer and editor before making the leap into interiors, working with the likes of 91 Magazine and copywriting for luxury bed linen brand Yves Delorme among others. She feels that fashion and interiors are intrinsically connected – if someone puts an effort into what they wear, they most likely also care about what they surround themselves with.