Dishwasher vs. Hand-washing Dishes: Which is better?
To dishwash or not to dishwash, that is the question!
At first glance, comparing the two methods of cleaning our pots and pans might seem relatively straightforward, but simple, the question is not.
Whether you’re a hand washer or a dishwasher user has long been the subject of jovial pub talks…
Dishwasher people are lazy, is often remarked, whilst hand washers are wasteful some might say.
Well, hold onto your hats because we’re going to break down this argument and once and for all find out what is the best way to wash your dishes.
Let’s start with energy consumption…
What is more energy efficient, hand washing dishes or using a dishwasher?
Practically every website we checked whilst researching this article claimed that dishwashers were far more energy efficient than hand washing dishes. However, none of them seemed to do any analysis or actually tell you how much energy is typically used when hand-washing dishes compared to using a dishwasher.
In the UK/EU, home appliances are rated according to their energy efficiency. The ratings start at A and end at G. A being the most efficient and G being the least efficient.
A typical energy efficiency label looks like this:
We checked one of the country’s leading appliance retailers and compared every freestanding dishwasher they were selling as of the 6th of October 2023. (You can find them here.)
In total there were 100 dishwashers available and we've broken down how many were available at each energy rating, the lowest price that you can find this type of dishwasher for and the stated energy use of each dishwasher (per 100 cycles).
Strangely, the dishwashers with an F rating varied hugely in energy efficiency, with some dishwashers using just 78kWh compared to others that used 104kWh.
These ratings’ systems are great for helping consumers understand which product is efficient comparatively, but how energy efficient are dishwashers when compared to hand washing?
Although we could not find any information which showed how much energy it took to wash dishes by hand, we found that the energy it takes to heat a shower (30 litres of water) is 1.4kWh.
Since a standard washing up bowl is around 12 litres we can assume that it takes roughly half this amount (0.7kWh) to fill a washing up bowl.
Okay… Here’s where the maths starts to get complicated.
Most people use a dishwasher roughly twice a week, meaning that in 50 weeks (350 days) the dishwasher will complete 100 cycles.
In the same time, we can assume that most people wash their dishes at least once/per day, meaning that they’ll use 245kWh in the same period of time that a dishwasher uses the amount of energy specified above.
So, Is a dishwasher more energy-efficient than hand-washing?
The answer is yes. In most situations a dishwasher is twice or more energy efficient as hand washing your dishes by hand. This may be skewed on an individual basis, but you can find out exactly how efficient your dishwasher is by reading the energy label - Details here.
How to choose an energy efficient dishwasher
In the UK, choosing a dishwasher that will save you money on your energy bills is relatively straightforward. Energy ratings from A to G are displayed by law on every appliance that is sold, giving consumers a clear picture of how efficient their appliances are.
In the US there are similar energy efficiency labels and you can find out more about how they work here.
What is the cheapest way to wash dishes?
To work out what the cheapest way to wash dishes is, we’re going to compare the costs of owning a dishwasher for 10 years vs. hand washing your dishes for 10 years.
Since 10 years is the average lifespan of a dishwasher, this seems reasonable.
This chart shows the cost of buying a mid-range dishwasher which uses an average amount of energy at the average energy price.
It factors in that you’ll buy dishwasher tablets & washing up liquid in bulk and use reusable and sustainable dish brushes.
We’ve taken the average amount of water a dishwasher uses per cycle here and assumed that if you hand washed dishes you’d use 6 litres of water per day.
So, is using a dishwasher cheaper?
It turns out that yes, it is cheaper. Over 10 years it will cost you around £2,379.50 to wash dishes vs. £3,397.00 if you washed them by hand.
This equates to roughly £100.00/per year that you’d save by using a dishwasher.
It should be noted that the main expense of washing dishes by hand was water. If you collect rain water or use less than 6 litres a day, then it may work out cheaper for you to wash your dishes by hand.
Do you really need a dishwasher?
For a lot of people, cost and energy consumption are besides the point. In a world where shared ownership housing has become the norm, not everybody has space for a dishwasher.
If you live in an apartment that only has a limited kitchen space you may decide to keep things simple and stick to hand washing your dishes.
In that case, how can you make hand washing dishes more energy efficient and cheaper?
- DIY washing up liquid can save you money. You can purchase Castile soap in bulk and add a few other simple ingredients to create a basic dish soap. We’ve written a few quick recipes here.
- Using reusable dish brushes means that you only have the buy the handle once. You can then replace the head only. You can even set up a subscription to receive dish brush heads as and when you need them here.
- Be sure to use a washing up bowl. Collect the water that you use and pour one bowl for the day. You can find some basic washing up bowls here.
Other considerations when deciding between washing up by hand or dishwashing
Noise - Using a dishwasher may be more energy and cost efficient, but it’s also noisier. Expensive dishwashers will reduce the noise that they make but dishwasher noise still ranges from 40dB to 80dB, making it considerably noisier than washing up by hand.
Time & speed - We’ve all been there… You need plates but the dishwasher is full and nobody has turned it on. It’s frustrating and you then need to remove plates from the dishwasher which have food stained onto them to wash in a hurry. Dishwashers are great, but all of the calculations above are based on washing full loads. If you only have a limited amount of plates, take this into account.
Hygiene - Dishwashers use water that is heated to a much higher temperature than water from the tap. This has been shown to kill more bacteria than when dishes are washed by hand.
Dishwasher limitations - Wooden tablewares, delicate ceramics and large pots and pans can’t be washed in the dishwasher. Meaning that you likely will need to adopt a hybrid approach, washing some of your dishes by hand and some in the dishwasher.
This could mean that in the long run a dishwasher becomes less energy efficient and cost effective than reported, but this is entirely situational.