How much does a dishwasher cost to run?

A dishwasher heats water twice, once to wash and again at the end to help the dishes dry, and that's where almost all the electricity goes. The eco programme runs longer but heats the water less, so it's the cheapest setting despite taking hours.

How we work it out

A typical dishwasher uses about 1kWh for eco programme, taking around 2.5 hours. Electricity on a standard variable tariff costs about 26p a unit across Great Britain at the moment (it varies a little by region), so one run comes to about 26p. Your own model may use more or less: the energy label, or a plug-in energy monitor, will tell you.

If you're on a tariff where the price changes through the day, such as Agile Octopus, Economy 7 or an electric car tariff, the same run can cost much less at the right time. The Cheap Watts tool finds that time for you on your own tariff.

How to spend less

• Use the eco programme. It's slow because it's cheap, not the other way round.
• Run it full. A full load costs the same as a half one.
• Skip rinsing plates under the hot tap first: scrape them instead.
• Open the door at the end instead of using the heated dry, if your machine lets you.