Jun 03, 2021

3 Zero Waste Reasons to Use Your Dishwasher

by Krystina Jarvis

Listen to the audio of this post here:

This post first appeared in our weekly Make Waves Mondays email series on May 31, 2021, and was updated and re-shared again on May 25, 2026.

Hello hello friend!

We are BACK today with another edition of Small Change Big Impact — our monthly mini-series within Make Waves Monday where we highlight just one small change that can have a big impact for the planet…without much thought or effort.

And today we’re talking about doing the dishes.

Specifically, we’re answering the question: which is more sustainable — running the dishwasher or washing the dishes by hand?

It’s one of those things that never ends (though I try my best to remember that that’s a good thing, because it means there’s food on my table), so if there’s a more sustainable way to do it, well why the heck not give it a try??

And the good news is: the more sustainable way is also the easier way.

How often does THAT happen??? 😅

But yes, running your dishwasher is by far more sustainable than hand-washing. It’s a win-win if I’ve ever heard one.

So, friend, put that loofah down and let’s dive in 👇

Water Savings

Even with a low-flow faucet installed, running your kitchen faucet uses anywhere from 1.5 to 2.2 gallons of water per minute.

Energy Star defines a “standard” dishwasher as being able to hold at least 8 place settings (forks, knives, spoons, plates, glasses, etc.) plus 6 serving pieces. So about 54 pieces of dishware.

Assuming you have a low-flow faucet that uses 1.5 gallons of water per minute, and a standard dishwasher that uses 5 gallons of water per load, if you’re washing all of those dishes by hand, you’d have just about 3.7 seconds to wash and rinse each dish before you’ll have used more water than your dishwasher would.

If you have an Energy Star certified dishwasher that uses just 3.2 gallons of water per load, that number drops to just 2.4 seconds to wash and rinse each dish.

But it takes an average of about 15 seconds to hand wash one dish, which means that to wash the equivalent of a full dishwasher-load of dishes by hand, most of us will use about 20 gallons of water.

That’s more than 150 bottles of water just to wash one load of dishes by hand, and a whopping 75 to 84% reduction in water use to use your dishwasher rather than washing by hand. WHAT 😳

PLUS — here’s a fun fact I recently learned:

Newer dishwashers actually work by sensing how clean the water is. So they’ll spit out a little bit of water, wash the dishes, and sense how clean the water is as it drains. If the water isn’t clean, it’ll spit out some more water and repeat until it senses that the water is clean.

So your dishwasher isn’t just spewing water on your plates for an hour.

It’s actually measuring how clean your dishes are and adjusting accordingly.

How cool is that???? Talk about zero waste…

Photo by Nathan Dumlao on Unsplash

Energy Savings

Okay so this one also surprised me. Did you know that most dishwashers actually have a built-in water heater that’s more efficient than the one in your basement?

To heat just two gallons of water flowing from your faucet uses about 0.3 kilowatt hours (kWh) of electricity.

And like we just established, if you’re washing a full load of dishes by hand, you’re likely using about 20 gallons of water. To heat those 20 gallons of water, you’re using about 3 kWh of electricity.

That’s about 2.6 pounds of carbon dioxide emissions, or the equivalent of driving about 3 miles in an average passenger vehicle.

Now let’s say you do the dishes just 182 out of the 365 days of the year (about every other day). That’s about 546 kWh, or 474 pounds of carbon dioxide emissions — or the equivalent of driving about 547 miles.

That’s more emissions than driving from San Diego to Sacramento.

But using a dishwasher, on the other hand, uses less than half of that energy. Energy Star certified standard dishwashers can use no more than 240 kWh per year.

That cuts your emissions to just 234 pounds of carbon, or the equivalent of driving about 271 miles — just a touch further than driving from San Diego to Bakersfield.

Time + Money Savings

The average residential water rate in the US is $7.74 per 1,000 gallons, and the average residential electricity rate in the US is $0.173 per kilowatt hour.

If you did one full load of dishes every other day in an Energy Star certified dishwasher rather than by hand, you’d save about $24 on your water bill and about $53 on your electricity bill every year, for a total of about $77 a year on your utilities!

And — potentially even more exciting — is the amount of TIME you can save by using your dishwasher.

When you use your dishwasher, you’re really only loading and unloading, which takes, what?, 6 minutes?

When you’re washing those dishes by hand and they’re each taking you 15 seconds (on a good day), AND THEN you still have to put them away, that’s gonna take you at least 15–20 minutes.

Even if running the dishwasher only saves you 10 minutes per load (and let’s be real — it’s WAY more than that), that’s still a whole 30 HOURS of your life that you’ll get back in a year.

I don’t know about you, but if I can save $77 and 30 hours of my life every year, you can bet your behind I’m gonna do it 👀

Other Ways to Save Waste

If you really wanna step up your waste-saving dishes game, scrape your dishes into a compost bin rather than rinse into your disposal. If your dishes do need a rinse, the sooner the better, rather than letting the food remnants dry first.

And if you’re washing things by hand (I personally do all of my pots and pans, wooden cutting boards and spoons, and coffee mugs by hand), turn off the faucet whenever you can. Get your dish brush or loofah wet enough to create a nice bubbly lather with your dish soap (or dish soap bar), wash a few dishes at a time, and rinse them together.

Bonus: If you prefer to fill your sink with water, try a large pot instead! You’ll use less water that way 😄

A Drop in the Ocean Tacoma Zero Waste Sustainable Living Shop Refillable Dish Soap Natural Loofah

A quick note…

Keep in mind that all of these are generalized numbers, and applicable for full loads.

Unlike certain dishwasher detergent brand commercials promote (*cough cough* Cascade *cough cough*), please do not run your dishwasher every day for just a couple of dishes. That math just doesn’t work.

That brand is greenwashing you into using more water, more energy, and MORE OF THEIR PRODUCT (that’s full of chemicals that aren’t people- or planet-safe), by promoting using the dishwasher for just a few dishes every day because it’s “more sustainable.” 🙄

It’s not.

Don’t let ‘em greenwash you. You’re better than that. You’re an EcoWarrior, goshdarnit!

So friend, in summary… Press “start” on that dishwasher of yours and rest easy knowing you’re taking small actions that have a big impact on the planet and people 💙

P.S. To take your sustainable dishwashing routine one step further, check out our post about all the reasons to turn off heated dry on your dishwasher!