How much does a dishwasher cost to run — and will hand washing save money?

'How much does a dishwasher cost to run?' is a question you might wonder each time you load one up. 

A dishwasher is a wonderful thing: not only does it serve as an excellent place to hide dirty dishes, they come out clean at the push of a button. Disagreements over how best to stack a dishwasher notwithstanding, these devices can be the difference between a happy life and arguments over the last clean mug.

But while dishwashers were once considered a luxury, these days they’re generally the preferred option over getting out the marigolds and doing the dishes by hand. 

With looming energy shortages and suggestions about energy saving tips leading us to examine every kilowatt we expend on household tasks, we’ve dug into the costs and whether or not it is worth considering switching back to hand washing while energy costs remain high. 

How much does a dishwasher cost to run?

Domestic unit rates for electricity are estimated at around 34p per kWh from October 2022, according to energy regulator Ofgem, following intervention from the Government with the energy price guarantee. This will now only last until April 2023, with average energy prices expected to rise for consumers after that.

With these higher rates, the cost of running a dishwasher seven times a week for a whole year is going to go up. 

The average full size dishwasher consumes around 1kWh per load and the average slimline dishwasher is a fraction lower at around 0.8kWh per load, according to our research into affordable dishwasher models including this F-energy rated full size dishwasher on John Lewis that uses 1.03kWh and this F-energy rated slimline machine on John Lewis that uses 0.78kWh per cycle. 

We’ve broken down the average costs for you:

If you want to apply the calculation to your own dishwasher at home, all you need to do is find the kWh per load figure in your paperwork (this may be per 100 loads so you'll need to divide it by 100 to get the per load figure).

You then calculate: kWh per load x 0.34 (or the price per kWh you pay for electricity) to get the cost per load. To get the cost per week, multiply this by 7, or cost per year, multiply by 365.

Which dishwashers are the cheapest to run?

As with lots of things, smaller is more economical when it comes to dishwashers. If you use a slimline or a drawer dishwasher, you’re likely to use less water and electricity, which is cheaper.

Having said that, there are full-size dishwashers with A-rated energy efficiency ratings (that is A-rated on the new scale introduced in 2021 as the old scale A** rated would only be an F now). They cost more to buy in the first place but could save you money and help the environment over the longer term.

Good examples of energy efficient models include this A-rated freestanding Miele dishwasher which only uses 0.54kWh per load or this A-rated integrated dishwasher from Siemens, which again only uses 0.54kWh per load.

Is it cheaper to run a dishwasher or hand wash?

Generally, dishwashers are considered more economical than hand washing, as well as having a better carbon footprint. This is because they use less water and take less time to heat up the water than the equivalent of running a tap would.

Running a dishwasher cycle roughly equates to heating four to six washing up bowls full of water or running the hot tap for six to nine minutes, according to utilities expert Sofia Hutson at Compare the Market. 

This means if you have lots of dirty dishes and a reasonably energy efficient dishwasher that is stacked correctly, it can be cheaper to use a dishwasher than wash by hand. This is also assuming that energy prices don't jump much higher than 34p kWh, as they are on average between October 2023 and April 2023.

To break it down further, on average a dishwasher uses 9.5 to 14 litres of water per cycle, compared to a kitchen tap, which produces roughly 6 litres of hot water per minute. Some more efficient dishwasher models use even less water than that like this Siemens model that only used 7.7 litres during its eco cycle.

That said, if you’re efficient with how you use water when you do the dishes (for example, not running hot water to rinse and not refilling the bowl too many times), you could still beat the dishwasher to save money. 

How can I improve the efficiency of my dishwasher?

It might seem like a source of marital arguments, but how you stack the dishwasher counts. Make sure you properly fill your appliance before running it, and always choose the right setting.

Keep your dishwasher topped up with salt and rinse aid, and use the eco setting if you can. Scrubbing any remaining food off plates can help with efficiency, too. Pre-rinsing is not usually necessary for newer models and again will save you pennies if you avoid it.