How much water does a dishwasher use?

Let’s get right to the big question: does running the dishwasher save water? The answer is: it depends on your model. A standard, energy-certified dishwasher will use around 11 litres of water per washing cycle. Older appliances can waste up to 38 litres per cycle, while those built after 2013 tend to use around 19 litres. Compare that to washing the same number of dishes per hand in a sink which can waste up to 102 litres of water. Yes, manual washing isn’t quite the water-saving alternative it’s made out to be. 

But water is only one factor of course. Dishwashers use energy and here the same rule applies: more energy-efficient models will use less energy. The average appliance uses 1800 watts of electricity. That’s about the same as a radiator. Say you’re running a machine that uses 1800 watts of electricity for a normal load and your current electricity rate is £0.17 per kWh, you’d pay £0.22 per load and around £5.60 per month if you use the appliance every day. 

Not necessarily. There are many other costs to consider when running a dishwasher such as the washing tablets, which can easily cost £0.10 to £0.30 per wash depending on the brand you choose. Typically, the well-known brands tend to be slightly more expensive. 

By comparison, washing up liquid can cost between £0.50 to £3 for an entire bottle that lasts up to 20 to 30 washes. 

Water costs depend on how much water you use. If you spend an average nine minutes washing dishes under hot running water or fill more than six bowls regularly, a dishwasher could be more cost-effective. 

The appliances tend to work with water that’s heated to around 50°C. You wouldn’t normally wash your dishes in the sink at such a high temperature. That’s why dishwashers tend to clean dishes more effectively as long as you maintain them well and clean their filters regularly. 

There are a couple of things you can do to make the dishwashing process even more energy and cost-effective.

1. Buy an energy-efficient model. If you’re in the market for an upgrade or it’s your first time buying a dishwasher, go for an energy-efficient model. Many providers label their appliances with energy ratings. So watch out for them.
2. Load the dishwasher fully. You’ll want to make sure that the dishwasher is always fully loaded before switching it on. In this way, you’ll be running fewer loads per week and thus waste less energy and water.
3. Avoid pre-rinsing. By pre-soaking or washing your dishes, you’ll be wasting additional water. In fact, this could waste over 22,000 litres of water in a single year! So allow the dishwasher to do all the work. Most of them should handle even baked-on crusts efficiently, especially when using a good dishwasher tablet.
4. Choose the energy setting. Many newer models now come with energy settings. You can run dishwasher loads at temperatures as low as 40°C.
5. Swap your dishwasher settings to air-dry your loads. To save even more electricity, you can switch off the electric heat on most appliances. This means your dishes will be left to air-dry and you’ll save energy and money. 

Now you know how many litres of water a dishwasher uses, find out how to clean your dishwasher, how to unblock a sink and how to decipher washing symbols in our other handy dandy articles.