Is It Cheaper to Wash Dishes by Hand or to Use a Dishwasher?
The short answer: It depends.
Let’s explore both options to identify strategies that can save you money.
Using a Dishwasher
About 70% of homes own a dishwasher, but only about 55% of households actually use a dishwasher at least once per week. This makes dishwashers one of the least used appliances at home (EIA photo). To calculate the annual cost of running a dishwasher, you need to know 4 things:
- The amount of gallons of hot water your dishwasher uses per load.
- The electricity required to operate your dishwasher during each cycle.
- The quantity of times you run your dishwasher in one year.
- The prices you pay your utility companies for water, electricity, and natural gas (if you have a natural gas water heater).
How Much Hot Water Does Your Dishwasher Use Per Load?
The average dishwasher uses 6.1 gallons of hot water per load. The oldest dishwashers use as many as 10 gallons per load, while the newest EnergyStar dishwashers use only 3 gallons per load. Check your dishwasher manual to see how many gallons of water your dishwasher uses per load.
Operating Electricity of a Dishwasher
In addition to the price you pay for the hot water that is used in the dishwasher, the dishwasher itself requires electricity to operate its pumps, sensors, and controls. Many dishwashers draw between 1200 Watts and 2400 Watts of power. So if you run a 1200-Watt dishwasher for 1 hour, that means you have used 1.2 kiloWatt-hours (kWh) of energy. You can find the wattage of your dishwasher on its specification plate or in the owner’s manual.
How Often Do You Use Your Dishwasher?
Before the COVID-19 pandemic, the average US household used their dishwasher about 215 times per year. This means they used the dishwasher 3 times every 5 days. Since eating and cooking at home has become much more common since the start of the pandemic, households are most likely using their dishwashers much more often than before. The EIA’s RECS data states that the average household that uses a dishwasher consumes about 113 kWh per year to operate the dishwasher.
What Prices Are You Paying for Water and Energy?
Because dishwashers use hot water, you need to consider both the cost of the water and the cost to heat that water in your water heater. The average water utility company charges $0.015 per gallon of water, so you would simply multiply this number by how many gallons your dishwasher uses per load.
The average US household spends $296 per year to heat the 16,608 gallons of hot water that they use throughout the year. This averages out to an energy cost of $0.018 per gallon of hot water. But this cost can drastically change based on your water heater technology and whether you use electricity or natural gas to operate your water heater. Check out our Water Heater episode to learn how to determine a more accurate water heating cost for your home.
Lastly, since the dishwasher itself requires electricity to operate, you need to know the rate you pay for electricity. The average electricity company in the US charges $0.12 per kWh.
What’s the Total Cost for Operating a Dishwasher?
Let’s assume a dishwasher uses 6.1 gallons of hot water for each of its 215 cycles per year. Let’s also assume an average water and electricity rates of $0.015/gallon and $0.12/kWh, and an average annual cost of $296 to heat the 16,608 gallons of hot water used per household per year. For the operating electricity costs of a dishwasher, let’s assume the 113 kWh per year that’s stated in the EIA’s RECS data. Summing these expenses, it costs about $57 per year to run the average dishwasher.
But Wait! What If I Rinse the Dishes Before Loading the Dishwasher?
At least 50% of households rinse their dishes before putting them in the dishwasher. This was verified by a ### study that showed that average sink usage did NOT decrease in homes that used a dishwasher. So if you rinse your dishes before putting them in the dishwasher, you have to pay $57 (calculated above) PLUS the cost of the water you use from your sink. So if you use just 6 gallons of hot water to rinse dishes per day, that adds another $72 per year to your dish washing expenses. That means the total cost would be $129 per year.
How You Can Lower Your Dishwasher Expense
Scrape, Don’t Rinse
Instead of rinsing your dishes before putting them in the dishwasher, you can scrape any chunks of food or sauce off with a fork or knife. The dishwasher is powerful enough to clean the rest.
Clean and Maintain Your Dishwasher
You will see the best cleanliness results from your dishwasher if you regularly maintain the sensors, filters, water jets, and drains. This regular maintenance will also allow your dishwasher to have a longer lifespan.
Run Full Loads
Only run your dishwasher if it is completely full. If your household doesn’t use a lot of dishes at a time, be sure to purchase a compact dishwasher instead of the standard size. If your dishwasher is too small for your needs, you’ll cycle it so much that it won’t last as long as it should. And if your dishwasher is too large for your needs, you’ll waste a lot of energy and water by running it when it’s not full.
Check Your Settings
Many dishes have several options for different types of wash cycles. Strangely enough, sometimes the “shorter” cycles can actually use more water. So make sure to read your dishwasher’s manual to learn which cycles use the least hot water. Furthermore, many dishwashers have the option to dry your dishes with hot air. Make sure to disable this setting. You can save up to 15% of dishwasher energy costs by air drying dishes instead of heat drying them
If you upgraded to an EnergyStar dishwasher that uses only 3 gallons per load and if you already upgraded to a heat pump water heater, you would spend only $28 per year to run your dishwashers.
Can You Save Money By Hand Washing Your Dishes?
Some households can use as many as 25 gallons of hot water per day to wash their dishes by hand. Using the average prices for water and water heating mentioned above, this clocks in at about $300 per year! Even if your household uses only 10 gallons of hot water per day to wash dishes, that’s still about $120 per year.
Let’s assume you have an efficient heat pump water heater and that you use all hot water to wash your dishes. You would have to use under 3.4 gallons of hot water per day to wash dishes to spend less money than you would to run an EnergyStar dishwasher without pre-rinsing your dishes.
Tricks for Lowering Your Hand-Washing Expenses
- Turn off the water. If you turn off the water while you’re scrubbing your dishes, you can save significant amounts of water and energy. An easy strategy is to plug your sink while you’re rinsing your first few dishes and let the soapy water accumulate. Then you can use that accumulated water to wash the rest of the dishes.
- Wait until you have a stack of dirty dishes. By washing more dishes at a time in the water you accumulated in your plugged up sink, you can use less water per dish.
- Use cold water. Using cold water to clean your dishes completely eliminates the water heating expenses for using hot water.
- Be wiser about dish choice. You can reduce the amount of dirty dishes by being smarter about your dish and utensil choices while eating and cooking. You can even reuse dishes if they aren’t that dirty, but make sure to keep your eating environment clean to avoid the spread of germs, especially if you live with others.
- Dry with a reusable rag. If you use a cloth rag to dry the dishes, you can save on paper towel costs too.
Disclaimer: Please consult with a professional before making any upgrades to your dishwasher, kitchen, or home. Any and all upgrades should maintain proper health, safety, and sanitation levels within your homes. It All Adds Up and its affiliates are not responsible for any household damage or personal injuries that should occur from following any suggestions from It All Adds Up.