Dishwasher vs handwashing: which is the most efficient method?

Our in-depth testing has found that dishwashers, on average, use almost 80% less water per full wash than washing up by hand. 

Switch to eco mode and a dishwasher uses even less water. Even a relatively inefficient model still trounces handwashing in terms of water use.

Here, we break down how water and energy use compare between using a dishwasher and handwashing dishes in the kitchen sink.

Inspiring tips for improving the place you live in. Get our Home newsletter – it's free monthly

Dishwashers vs handwashing

When washing up by hand, we estimate you can clean around two place settings with one washing-up bowl (with an average capacity of nine litres) before you need to empty and refill it.

However, most dishwashers don't just wash one or two place settings at a time; we've tested some full-sized models that will do up to 16 sets in one wash. 

Slimline dishwashers will handle around eight to 11 place settings, and even compact dishwashers will do four to six place settings. 

So, all conventional dishwasher types will wash considerably more dishes in a single cycle compared to handwashing.

So, do dishwashers use more water? 

No, quite the opposite. 

Handwashing effectively uses 4.5 litres of water per place setting, but based on a sample of recently tested dishwashers (including a mix of efficient and not-so-frugal models), we estimate that it would take just under one litre of water per place setting in a dishwasher.

Washing 14 place settings by hand would use 63 litres of water, compared to an average of 12.96 litres when using the main wash cycle on our sample of dishwashers. Switch to eco mode and that drops down to 696 millilitres per place setting, or just under 10 litres for a 14 place settings. 

So there really is no debate – dishwashers use less water than handwashing.

We measure how much energy and water each appliance uses to find the most energy-efficient dishwashers

What about energy use?

This is where the comparison gets a little trickier. 

Dishwashers on average use about 1.12kWh of energy per wash, which costs roughly 29.5p*. How much energy is used to heat up water for your washing-up bowl will depend on the heater. 

If you have a gas-heated water tank, it isn't an easy comparison (a bit like apples and pears), but gas is typically cheaper than electricity. If using an electric immersion heater that's 3kW, it will cost roughly 11p* to heat up a nine-litre washing-up bowl. 

That's obviously cheaper than the dishwasher, but just remember that it will only wash two place settings, whereas the dishwasher will clean considerably more.  

*Based on the October 2025 energy price cap of 26.35p per kWh 

As well as the best dishwashers, you can also discover the best dishwasher tablets and best washing-up liquids according to our tests