If you were raised in a household where an adult insisted that hand washing dishes saved more water compared to the dishwasher, you’re not alone. Many of us grew up believing that running the dishwasher was wasteful, in terms of both electricity and water. After all, why would loading up a bulky machine with plates, glasses, and silverware possibly be more efficient than a few quick scrubs in the sink?

As it turns out, the belief that hand washing saves water is more myth than fact. Modern dishwashers have come a long way in efficiency, and our hand washing habits often involve far more running water than we realize. To settle the debate, we consulted a plumbing expert who broke down the real numbers behind dishwashing, and the truth might make you rethink your after-dinner cleanup routine.

Paul Abrams is the director of public relations and spokesman for Roto-Rooter Services Company.

Does Hand Washing Use More Water?

To settle the debate, we consulted with Paul Abrams, director of public relations and spokesman for Roto-Rooter Services Company. “Dishwashers typically use three or four gallons [of water] per wash cycle, whereas washing dishes by hand can use over 25 gallons per wash session,” he explains. That’s a jaw-dropping difference, and the numbers don’t stop there. “Running a kitchen faucet for five minutes uses approximately 15 gallons of water, and most people who wash dishes by hand keep the faucet running most of the time,” Abrams adds.

In short, yes, hand washing uses more water than a dishwasher.

Even if you’re conservative with your water use at the sink, it’s nearly impossible to beat the efficiency of a dishwasher. According to Abrams, “A homeowner will use seven to eight times more water washing dishes by hand than by using a dishwasher.” So, think about that the next time you let the tap run while scrubbing pots and pans. What feels like a quick rinse actually sends gallons of water down the drain.

What If You Fill the Sink?

Maybe you’re thinking, ‘Well, I don’t let the faucet run the whole time, I just fill the sink and wash, so that’s OK. Right?’ It’s a fair point, but even this method isn’t quite as helpful as you might expect.

“The average kitchen sink pan is 7 to 10 inches deep and holds 10 to 15 gallons of water,” Abrams says. “That amount of water far exceeds the three to four gallons a dishwasher would use in a normal cycle.” Even the most conscientious hand washers who use a basin or a full sink still use two to four times as much water as the average dishwasher cycle. While it’s better than leaving the faucet running endlessly, the numbers are still clear: the dishwasher wins.

What If You Only Have a Few Dirty Dishes?

If you’ve ever hesitated to run a cycle because you only had a few plates and glasses, you might be onto something. “Roto-Rooter recommends waiting until the dishwasher is full before running it,” Abrams says. “Adding dirty dishes to the racks until the dishwasher is full is the most efficient way to use a dishwasher.”

That means loading the dishwasher throughout the day (or over a couple of days) until you can run a full cycle. Modern appliances and detergents are designed to handle dishes that sit for a bit before being washed, so you don’t need to worry about smells or stuck-on food as long as you scrape plates before loading.

At the end of the day, however, no matter how full they are, dishwashers still save water.

How Modern Dishwashers Save Water

If you’re still skeptical, consider this: dishwashers have been engineered over the last several decades to maximize both water and energy efficiency. This isn’t just good for your utility bill; it’s also good for the environment.

As Abrams points out, using certain dishwasher settings can make a significant difference. “Look carefully at the options your dishwasher offers and experiment with the quick wash and eco wash features to see if they meet your everyday needs,” he suggests. “These settings use less water and electricity but will clean your dishes very effectively, especially when you aren’t washing dishes with heavy, stuck-on foods like lasagna.”

Pay Attention to Detergent, Too

It’s not just about the appliance, it’s also about what you put in it. Abrams recommends pairing those water-saving dishwasher settings with a concentrated detergent. “You’ll get better results when you combine the more efficient dishwasher settings with a high-quality, concentrated detergent like Cascade Platinum Plus pods, which are designed to clean more efficiently and dissolve grease before it goes down the drain and causes problems,” he says.

So not only do you save water, but you also avoid potential plumbing issues caused by grease buildup. That’s a win-win for everyone and everything involved.