Washing machine temperature guide
By Matt Stevens
Find out which temperature to wash at and what happens to your clothes – and bills – when you change your washing machine temperature to 20°C, 30°C, 40°C or 60°C.
For the majority of us, laundry day means washing the bulk of our clothes at 40°C. But there will be occasions where we need to wash hotter or cooler to best clean our clothes while protecting the fabrics.
Our washing machine temperature guide will help you to decide which temperature to wash your clothes at, whether you're washing jeans, whites, coloureds or baby clothes.
If you're in the market for a new washing machine, head straight over to our washing machine reviews.
Or read on for the answers to these clothes washing questions:
- Can I wash clothes at 20°C?
- What are the benefits of washing at 30°C?
- What's the difference between washing at 30°C and 40°C?
- What to wash at 50°C?
- What's the cost of washing at 60°C?
- Does washing at 90°C kill bacteria?
- What temperature should I wash denim jeans at?
- What temperature should I wash bed sheets at?
- What temperature should I wash baby clothes at?
- What temperature should I wash underwear at?
- Is 30°C a cold wash?
- What temperature is warm in a washing machine?
- What temperature is a hot wash?
- What temperature should I wash white clothes at?
- What temperature should I wash mixed coloured clothes at?
- What are other commonly used washing machine programs?
The answer is yes, you can, depending on the stain.
Since 2013, all washing machines in the UK have been required to have a 20°C option visible on the control panel to help save energy.
When we tested machines on the 20°C cotton program, we found that turning down the temperature from 40°C dramatically reduced running costs – by an average of 66%. This is because washing machines need to use less energy to heat water to lower temperatures.
And we found that cleaning power is only slightly worse at 20°C than at 40°C, with just an olive-oil-based stain not washing out as well.
Also see our guide: How to wash clothes
Using 20°C instead of 40°C could reduce running costs by 66%
More than a quarter of Which? members use a 30°C program on a regular basis. As you might imagine, it's the recommended setting for a lot of delicate clothes, such as wool and silk – always check the label first though.
Lower temperatures are also good at helping to preserve colourfully dyed fabrics, although a good quality laundry detergent can help with this, too.
Similar to the 20°C cotton programs we tested, it was the olive-oil-based stain that didn't wash out as well at this temperature when we ran tests. More general soiling was also lifted compared with washing at 20°C.
Costs are slightly higher for washing at 30°C compared to 20°C. When we tested the 30°C cotton program, we found that running costs are reduced by about 46% compared with the 40°C program.
While a 30°C program is good for delicate fabrics, a 40°C wash is ideal for more hardy fabrics. It’s suitable for cotton, linen or viscose, acrylics, acetate, wool mixtures and wool/polyester blends – in other words, most everyday items. This is possibly why it is the most common wash temperature used by Which? members.
As most Which? members we asked frequently use the 40°C temperature setting, we base our testing on the 40°C cotton and synthetics wash programs.
This wash is suitable for polyester/cotton mixtures, nylon, cotton and viscose, but with modern detergents most people find 40°C adequate for their needs.
The 60°C program generally delivers slightly better cleaning than the 40°C program, especially when it comes to greasy stains, and is ideal for bedding and towels. But it will cost you – running costs increase by more than half if you wash at 60°C as opposed to 40°C.
You might be washing at 60°C because you've heard it kills bacteria. The temperature on its own doesn't. Some bacterial spores and viruses are resistant to washing at 60°C. You need to combine your 60°C wash with a good detergent to blast that bacteria.
This is the hottest wash program you’ll find on most machines and is only suitable for some items – a lot of washing labels won't recommend washing at such a high temperature.
But will washing at 90°C actually kill bacteria? The NHS website states that you should wash underwear, towels and household linen at 60°C to prevent the spread of germs, but says nothing about washing at as high as 90°C to kill bacteria. It also says that you should use a bleach-based product, ie washing powder, combined with your washing program. This combination is the key to killing germs, as some bacteria will withstand 60°C temperatures.
Denim can shrink and colours will fade, so to avoid shrinkage and to keep you blue jeans blue, don’t wash them at more than 40°C.
If your washing machine has a specialist jeans program – and you have the time to split and separate your wash like this – this will use more water to flush away detergent and spins more gently to avoid creasing.
Find out more on how to wash denim jeans, baby clothes and underwear in our guide How to wash clothes
Select the 60°C cottons program for cotton bed sheets. By washing bed linen, such as sheets, pillow cases and duvet covers, at 60°C – and by using a Best Buy washing powder and laundry detergent – you give yourself a better chance of getting them clean without using the highest temperature setting.
Aim for 30°C or 40°C wash program for baby clothes. Any hotter and you run the risk of shrinking what can be quite delicate clothes.
You can wash your baby’s clothes with the rest of your laundry or, if your machine has the option, try the baby program.
This will be a little hotter but rinses thoroughly – more so than on a normal wash setting – to make absolutely sure that as much detergent as possible has been rinsed away.
If you end up with a pile of pants to wash, set your machine to wash at 60°C for the best results. If your load is very heavily soiled, wash at the highest temperature you can find, which is 90°C on most machines.
No, a cold wash will be colder than this and should involve no heating of the water at all. But some detergents won’t be as effective at low temperatures. A cold wash is an option if you’re washing delicates or your clothes are brightly coloured and just need to be refreshed a little.
40°C will feel warm and, with some exceptions, most of your laundry will end up being washed at 40°C.
Think about 60°C as a hot wash and 90°C as a very hot wash. Reserve the latter for special occasions where your clothes’ fabrics are robust enough to stand up to the heat and need the temperature to help shift the stains.
Separating white clothes from coloureds is more important than the temperature you wash them at. If you separate them, you give yourself the best chance of avoiding colours from other clothes bleeding into them.
The temperature you wash at will depend upon how dirty they are and how robust the items are, and just how dirty they are.
If you’re just washing your white bed sheets and other linen, 60°C will be fine. If you have a filthy white rugby or a football kit that’s stained with mud, blood, grass and everything else a Saturday afternoon on the playing fields has to offer, try a higher temperature.
Washing a mixture of bright colours together is fine and only becomes a problem if any whites end up in the load. Again, 30°C would be a good temperature to wash and this will help the fabrics to retain their colour.
Find a great machine for washing coloured clothes among our washing machine Best Buys.
Washing machines often have as many as 20 programs for washing, rinsing and spinning. These can include a baby care wash that has several rinses to make sure as much detergent is removed from the clothes as possible, an easy iron program and intensive programs to help shift stubborn stains.
For more information on these programs and more, consult our washing machine jargon buster.