Are Dishwashers More Efficient And By How Much?

Dishwashers are often promoted as being incredibly efficient appliances. But are those just marketing ploys, or do these machines truly bring much more efficiency into our daily lives?

Yes, dishwashers are much more efficient in several different ways. Compared to manual hand-washing, dishwashers consume a lot less water and electricity. These appliances also reduce the carbon footprint caused by washing dishes, and free up your personal energy and time for use on other important tasks. Buying a dishwasher involves a significant upfront cost, but they will pay for themselves after one year.

Let’s take a deep and detailed dive into all the ways that a dishwasher is much more efficient at cleaning dishes than hand-washing them manually.

See Also: Are All Dishwashers Hardwired?

How Are Dishwashers More Efficient Than Hand-washing?

Overall, dishwashers are indeed more efficient than cleaning your dishes manually. But how exactly are they more efficient, and in what specific terms?

Well, the dishwasher’s efficiency can be measured in terms of the appliance cost, water and electricity usage, and greenhouse gasses produced.

But, of course, it’s also incredibly crucial to consider a dishwasher’s efficiency in terms of the physical energy and time spent cleaning dishes.

Let’s take a closer look at each of those efficiency areas in which dishwashers are clearly more superior.

Dishwasher Costs

The first area where a dishwasher is more efficient is in terms of dollars and cents. This idea might seem counterintuitive at first, seeing as how you’ll need to pay an upfront cost to purchase a dishwasher.

However, researchers have figured out that after one year of using a dishwasher, the savings generated by the machine would be enough to make up for its initial cost.

Most of the financial savings come from the time saved, as almost all of the dish cleaning tasks are automated by the dishwasher.

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To understand this better, remember the old saying that “time is money”. In simple terms, your dishwasher will save you plenty of time by automating the dish cleaning process. In addition, since you’re no longer standing in front of the sink scrubbing dishes, your time will be spent getting more things done and increasing your overall productivity.


Dishwashers are also incredibly efficient when it comes to water use. A standard dishwasher with an Energy Star label can use as little as 4 gallons of water per load. 

Related: Dishwasher Problems Caused by Hard Water

Some statistics even claim that newer dishwashers cut down water usage by 74% compared to older models. When compared to manual hand-washing, dishwashers use 33.5 litres (almost 9 gallons) less water.

The evidence is strong that dishwashers are incredibly efficient when it comes to using water. Here are two examples of how modern dishwashers have become much more efficient with water usage:

  • Water recycling: Firstly, a dishwasher is specially designed to recycle the water that it uses. For instance, once the spray arms inside have rinsed the dishes one time, that water will be filtered and recirculated to be used again. This process prevents wastage and reduces the overall water needed to run a successful dishwashing cycle.
  • Eco-Friendly Design: The dishwasher industry is incredibly competitive. Manufacturers are constantly working to improve their appliance’s eco-friendliness to cater to customer demands. In doing so, dishwashers from leading brands are continually becoming more efficient at using less water overall.


At first glance, it’s easy to assume that dishwashers are heavy-duty consumers of electricity. However, that’s often not the case. 

Firstly, the appliance’s electronics (e.g. control board) and pumps only use as much electricity as a blow dryer. So that’s not much at all.

Secondly, the one component responsible for consuming plenty of electricity is the dishwasher’s heating element. This part uses plenty of electricity to raise the water temperature to clean dishes more effectively. 

However, that heating element isn’t used so often. Why? Because many dishwashers can be connected directly to your household’s hot water line. That means your household water heater will send pre-heated water directly into your dishwasher, and the appliance can begin washing without turning on the heating element.

Another way to understand a dishwasher’s efficiency in terms of electricity is in dollars and cents. 

So, compare these electricity prices to operate dishwashers, from older models to more efficient newer ones:

  • $4.94 a month (dishwashers back in the 1990s)
  • $3.68 a month (older dishwashers with Energy Star ratings)
  • $3.16 a month (the latest Energy Star-rated dishwashers).

Greenhouse Gasses

Another method of measuring the efficiency of a dishwasher is by considering its carbon footprint. That means measuring how many greenhouse gasses are let out into the world to generate the power needed to operate the appliance.

In terms of greenhouse gasses, researchers have found that using a dishwasher is far more efficient than washing dishes manually.

For instance, when washing dishes by hand over ten years, 5,620 kilograms of greenhouse gasses are released. Researchers arrived at this figure by assuming 32 items were washed over those ten years.

But what about dishwashers? Using the appliance is only responsible for 2,090 kilograms of greenhouse gas emissions over the same period, with the same number of items being washed.

In simpler terms, washing your dishes by hand has almost double the carbon footprint compared to using a dishwasher. That is a necessary form of efficiency to consider, especially if you’re concerned about your dishwasher’s impact on the environment.

Personal Time and Energy

Of course, the efficiencies brought about by dishwashers go far beyond financial savings and a positive environmental impact. Dishwashers of all kinds are also incredibly efficient at reducing the overall time and energy spent dealing with dishes after a meal.

Automating the tedious process of washing dirty dishes, these appliances free up more of our limited time and energy that we can spend on more important things. That can mean spending more quality time performing other household tasks, thereby improving the overall efficiency and productivity in a person’s daily life.

How To Make Your Dishwasher Even More Efficient

As we’ve seen from all of the points covered above, modern dishwashers are incredibly efficient in so many ways. Still, there are steps that users can take to maximize those efficiencies even further.

Here are four methods you can use to maximize your dishwasher’s efficiency:

#1 Avoid Pre-rinsing

Resist the temptation to pre-rinse your dishes before loading them into a dishwasher. The whole point of a dishwasher is to wash all of your place settings at one time in as efficient a manner as possible.

By pre-rinsing dishes in a sink, you are reducing the overall efficiency of the process. That’s because you will be standing in front of the sink with a running tap spraying hot water. Not only will that increase your overall use of water and detergent, but it also means your water heater will be running more as well.

So, load them straight into the dishwasher and let the appliance handle the rest, no matter how soiled your dishes are.

#2 Load The Machine Fully

A dishwasher is similar to a washing machine in that it is more efficient when it is filled to the maximum recommended capacity.


A dishwasher is designed to wash place settings in bulk, all together at the same time. So, the appliance is most efficient when you load it with as many dishes as it can safely handle.

Even if you load too few items, the dishwasher will still need to use the same amount of electricity and water to complete the wash cycle. That would be a waste, which is why it’s always best to wash plenty of items all at once.

#3 Choose The Best Washing Cycles Or Programs

Modern dishwashers also feature plenty of innovative washing cycles or programs that you can choose from. 

For instance, most models will have Eco and Quick Wash programs. Both of these cycles run for much shorter periods, which means less water and power is used. That’s why such cycles are suitable when washing smaller items or if you only have a few dishes that you need to wash.

Related: Why Are Dishwasher Cycles So Long?

However, if your place settings are exceptionally soiled, you would better choose a more intense cycle. That way, you won’t need a second wash to remove exceptionally tough stains from your dishes. One cycle is all you’ll need, and in choosing so, you’ll also save water and power.

Many dishwasher models nowadays also come with Sensor cycles. During these cycles, the appliance relies on wash sensors to detect when the dishes inside are spotless. With those sensors, the dishwasher can prevent the cycle from running longer than necessary, therefore reducing water and electricity consumption.

#4 Use Off-peak Electricity

Depending on where you live, some locations have access to cheaper off-peak electricity. Once you know when those off-peak hours are for your location, you can pre-load your dishwasher and schedule it to run during those periods.

That will make your dishwasher much more efficient, as it will be using the same amount of electricity but for a significantly lower price.

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