How Many Gallons of Water Does a Dishwasher Use?

Whether it’s rising water bills or environmental concerns, people now more than ever want to know how much water their dishwashers use. The answer can vary significantly depending on the age, model, and ENERGY STAR rating of the appliance.

We look at how much water a dishwasher uses per load, per month, and per year for the average household. Many factors can have an influence on the efficiency of your dishwasher, including a few proactive steps you can take while using it.

How many gallons of water do dishwashers use?

On average, dishwashers use around four to six gallons of water per cycle, but this amount can vary significantly higher or lower depending on various factors.

For instance, if your dishwasher is ENERGY STAR rated, it will use a maximum of four gallons per load and as little as 2.35 gallons. On the other hand, if your dishwasher was manufactured before 1994, it likely uses between 9 and 14 gallons per cycle, according to leading dishwasher detergent brand Finish.

As you can see, the amount of water used can vary a lot, but  dishwashers are still more efficient than washing by hand. That’s because washing the same amount of dishes by hand as a full dishwasher load could use up to 27 gallons of water, or even 40 gallons, according to some credible sources.

Other factors that affect how much water a dishwasher uses

The age, model, and ENERGY STAR rating are not the only things that affect how much water a dishwasher uses. The wash cycle you select also makes a big difference. 

User manuals from dishwasher manufacturers show that “Heavy” wash cycles can use double or more water than “Normal” cycles. That means if your dishwasher’s listed water usage is four gallons, it could use eight gallons or more during a “Heavy” cycle.

Likewise, some cycles use less water than the listed usage for the “Normal” cycle, such as the “Eco” and “Rinse” cycles, which use around 30% or 60% less water, respectively. Another factor is whether you have a compact or standard size dishwasher. Compact dishwashers obviously use less water due to their smaller size—around 10 to 15% less, to be precise.

How much water does a dishwasher use per month or year

Again, this can vary a lot depending on various factors, such as how often you use the dishwasher. We’l just have to look at a few common examples.

The average household uses their dishwasher five times per week; however, people living alone and couples without children may use theirs as few as three times per week. If we say a month is 4.3 weeks, and a year is 52 weeks, we can make the following estimations:

• ENERGY STAR-rated, using 3.5 gallons per load: These dishwashers will use 75.25 gallons per month or 910 gallons per year if used five times per week. Or, 45.15 gallons per month or 546 gallons per month if used three times per week.
• Modern without ENERGY STAR rating, using 5 gallons per load: These will use 107.5 gallons per month or 1300 gallons per year if used five times per week. Or, 64.5 gallons per month or 780 gallons per month if used three times per week.
• Manufactured before 1994, using 10 gallons per load: These will use 215 gallons per month or 2600 gallons per year if used five times per week. Or, 129 gallons per month or 1560 gallons per month if used three times per week.

How to use your dishwasher efficiently

It has been proven that dishwashers are already way more efficient than hand washing, especially if you have a newer or ENERGY STAR-certified model. However, that doesn’t mean you shouldn’t take steps to use your dishwasher as efficiently as possible, to reduce your bills and help conserve water in your local area.

Here’s how to use a dishwasher efficiently:

Fill it

A dishwasher will use the same amount of water whether it has a full load of dishes or is half empty. Therefore, waiting until you have a full load before running a wash cycle will result in you running fewer cycles per month and year, resulting in less water usage.

Don’t overfill it

While you want your dishwasher to be full, you don’t want the plates, pots, and pans stacked on top of each other in a way that will obstruct the water jets. If you pack in too many items, some of them will come out still soiled, and you’ll have to run another cycle to clean them. Load the dishwasher racks until all the allocated slots are full, and stop there.

Scrape instead of rinsing

While this won’t affect your dishwasher’s water usage directly, it will affect household usage. Scraping your plates before putting them in the dishwasher will remove large pieces of food that could clog your appliance, giving you the benefits of rinsing without wasting water.

Upgrade to a newer model

If your dishwasher was manufactured before 1994, upgrading to a newer model will reduce water consumption considerably. ENERGY STAR certified dishwashers cost only $55 per year to run and can save you over 3500 gallons of water over their lifetime.

Maintain your dishwasher

Taking care of your dishwasher will also help ensure it runs efficiently for as long as possible. To maintain your appliance, remember to clean its interior regularly, use a suitable detergent, use the right amount of detergent, run it regularly, and get any issues fixed by a professional promptly. 

Summary

A dishwasher can use between 2 and 14 gallons of water per load, depending on its age and model. Since this range is quite wide, upgrading to a newer, more efficient model can be advantageous for those with dishwashers over a decade old. Either way, dishwashers still use considerably less water than hand washing, making them an important contributor to the conservation of our precious freshwater reserves.