Electric Water Heating Cost, kWh Usage Per Month (State-By-State RECS Analysis)

Electric water heaters run on electricity. In some states, you can check how many kWh does a water heater use per month from the utility bill. However, most of us don’t really get that data, or if we do, we don’t really know if the number of kWh water heater uses per month or electric water heating cost is normal for our state and home size. For example, $10 per month is normal, while $100 per month is not normal at all.

To help everybody understand how many kWh should a water heater use, we are going to look into the average water heater kWh use per month, and how much those kWh per month cost (state-by-state). In the US alone, we use 173 billion kWh of electricity for heating water per year (according to the RECS survey published by the US EIA).

 

We are going to use statistical analysis and segment the water heater kWh use by:

• Size of home. We are going to look into how many kWh below 1,000 sq ft to 3,000 sq ft or more homes use. It seems obvious that a 2,000 sq ft home will, on average, use more kWh for heating water than a 1,000 sq ft house. As we will see, this is paradoxically not the case.
• Region/State. Due to different inlet water temperatures, different states will have different average monthly kWh usage for heating water. The dataset we are going to use segments the kWh usage by region. We are going to calculate as accurately as possible what is normal kWh monthly usage state-by-state. Example: It seems like homes in Texas or California will use less kWh for heating water than in New York. That’s due to 57°F – 67°F inlet water temperature in the south vs. 35°F – 47°F inlet water temperature in the north (here is a map with inlet water temperature in the US by Rinnai). However, during the statistical data analysis of actual kWh usage, we will see that this is not the case at all (because colder states primarily use gas-powered water heaters).

Here are some interesting results from the analysis:

• Average electric water heating kWh usage (by region) ranges from below 70 kWh to almost 200 kWh per month.
• South Atlantic and East South Central states use the most kWh for electric water heating (more than 2000 kWh annually). Mountain states use the least (824 kWh per year).
• Average electric water heating cost ranges from $7.44 per month (Idaho) to $29.40 per month (Delaware).
• Electric water heater kWh usage seems to be independent of house size (due to bigger houses using gas water heaters).

Now, as you may have figured out, it’s quite hard to estimate how many kWh per month you should be using for water heating. There are, presumably, two ways how to calculate that:

• Using water heater size. This would be your 30-gallon, 50-gallon, 80-gallon, or electric tankless water heater. Most water heaters with a tank use a 4500-watt heating element; tankless units can draw anywhere from 6 kW to over 30 kW of electricity. We know that running a 4500W heater for 1 hour will use 4.5 kWh of electricity. But we don’t really know how many hours or minutes per day we use a water heater, do we run it at 100% output (or 80%, 60%, 40%), and so on. Here we also don’t account for the region we live in. Essentially, using water heater size to accurately determine monthly water heater kWh usage is a fool’s errand.

  

• Using government’s statistical data on water heater electricity usage. Every 5 years or so, the US Energy Information Administration releases RECS survey data (Residential Energy Consumption datasets), based on utility bills paid. The last full dataset, released in May 2018, is published here (you will see over 89 PDF and XLS datasets). Among numerous data points, this dataset includes total water heating kWh consumption for all US homes combined (segmented, amount other things, by home size and climate region). Example: There are 118.2 million homes in the US. 26.1 million of them are between 1,000 and 1,499 sq ft. These homes have used a total of 47 billion kWh for water heating.

If we can boil down these statistical government data adequately, we should get a good estimate of how many kWh does an electric water heater use per month (and annually). What is more, we can calculate how much does water heating cost per month (state-by-state), if we multiply the used kWh by the average kilowatt-hour price.

We are going to look at houses between below 1000 sq ft and 3000 sq ft and more in size and will use the climate region kWh usage data to estimate water heating electricity usage state-by-state. On top of that, we are going to list the average electric water heating cost for every state in the union as well.

Let’s start by breaking down US total water heating kWh data by house size. After that, we will use the climate region data to calculate the water heater kWh usage state-by-state. You will find the complete average water heater kWh usage per month and per year summarized at the end.

US Average Water Heater kWh Usage By Home Size (Below 1000 To Over 3000 Sq Ft)

Alright, from the Residential Energy Consumption by fuel dataset, we have these US total water heating kWh usages:

• There are 26.6 million homes sized below 1,000 sq ft. For heating water, these homes use 35 billion kWh per year.
• There are 26.1 million homes sized between 1,000 and 1,499 sq ft. For heating water, these homes use 47 billion kWh per year.
• There are 17.5 million homes sized between 1,500 and 1,999 sq ft. For heating water, these homes use 29 billion kWh per year.
• There are 14.1 million homes sized between 2,000 and 2,499 sq ft. For heating water, these homes use 20 billion kWh per year.
• There are 10.8 million homes sized between 2,500 and 2,999 sq ft. For heating water, these homes use 13 billion kWh per year.
• There are 26.6 million homes sized 3,000 sq ft or more. For heating water, these homes use 30 billion kWh per year.

Now, this is the raw data. We can recalculate the total US kWh water heater usage for each individual home per day, per month, and per year kWh water heater usage. All these calculations are assembled in this chart:

As we can see, the average electric water heater kWh usage ranges between about 90 to 150 kWh per month.

We see a very interesting phenomenon here; the bigger houses (3000+ sq ft) don’t use more kWh per month than smaller houses (below 1000 sq ft). It seems that the electric hot water heater usage per month is independent of home size.

This is primarily because bigger houses use gas water heaters are the primary water heating source. They may have an additional electric water heater to supplement the bigger gas one. If you check the average therms of gas used for heating analysis here, you can see that bigger houses use a lot more gas for water heating.

Here we have to keep in mind that these are total US averages. What about each state? Let’s have a look at the regional water heater kWh usage to see how many kWh we are using for heating water state-by-state:

Average Regional Electric Water Heater Usage

From the RECS dataset, the total electric heater kWh usage is sadly not given per state. Instead, the US EIA uses census regions and divisions for geographical locating. Don’t worry, we will estimate water heating kWh usage state-by-state from this RECS geolocation usage data:

• Northeast US is segmented into New England and Middle Atlantic. In New England (Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont), 5.6 million homes used 6 billion kWh for water heating. In Middle Atlantic (New Jersey, New York, Pennsylvania), 15.4 million homes used 15 billion kWh for water heating.
• Midwest US is segmented into East North Central and West North Central. In East North Central (Illinois, Indiana, Michigan, Ohio, Wisconsin), 20.0 million homes used 18.1 billion kWh for water heating. In West North Central (Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, South Dakota), 8.3 million homes used 10 billion kWh for water heating.
• South US is segmented into South Atlantic, East South Central, and West South Central. In South Atlantic (Delaware, Florida, Georgia, Maryland, North Carolina, South Carolina, Virginia, West Virginia), 23.5 million homes used 52 billion kWh for water heating. In East South Central (Alabama, Kentucky, Mississippi, Tennessee), 7.2 million homes used 19 billion kWh for water heating. In West South Central (Arkansas, Louisiana, Oklahoma, Texas), 13.8 million homes used 24 billion kWh for water heating.
• West US is segmented into Mountain regions (Mountain North, Mountain South) and Pacific. In Mountain states (Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Utah, Wyoming), 8.5 million homes used 7.0 billion kWh for water heating. In Pacific states (California, Oregon, Washington, without Alaska and Hawaii as per the United States Census Bureau), 17.9 million homes used 20 billion kWh for water heating.

Alright, we can use this data to first calculate the average water heater kWh usage by region, and then by state. Here is the region-based kWh usage, followed by state-by-state water heater kWh usage:

Alright, here we see major differences. The water heater kWh usage per month ranges from as low as below 70 kWh to almost 200 kWh.

States with the highest average water heater kWh usage are South Atlantic and East South Central states. These include Delaware, Florida, Georgia, Maryland, North Carolina, South Carolina, Virginia, West Virginia, Alabama, Kentucky, Mississippi, and Tennessee. In these states, electric water heaters using 200 kWh per month is not unnormal.

We see the lowest kWh water heater usage in East North Central and Mountain states. These include Illinois, Indiana, Michigan, Ohio, Wisconsin, Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming.

Here is the important explanation:

The states with cold climates, on average, have a lower water heater kilowatt-hour usage. At first, this seems paradoxical. This is mostly because, in these colder states, homeowners will prefer more capable gas water heaters (instead of electric water heaters). Electric water heaters in colder states (like electric boilers or electric tankless water heaters) are used as secondary or backup hot water heating units.

Based on this data, we can estimate kWh water heater usage state-by-state. Maybe even more importantly, we will look at how much does it cost to run electric water heaters in all states (based on the average cost of electricity per kWh in a specific state).

Here is the state-by-state water heater kWh usage and the respective cost of running an electric water heater:

State-By-State Average Electric Water Heating Cost

Here, we will use the regional segmentation and census statistics for kWh usage. To calculate the average electric water heating monthly running cost, we will multiply the kWh used by the price of electricity. For the residential electricity prices per kWh, we will use this state-by-state EIA dataset for 2022 October kilowatt-hour prices. Example: In October 2022, the average price of electricity in California was 25.49 cents (US dollar).

Here is the full state-by-state water heater monthly kWh usage and cost:

As you can see from this chart, the average electric water heater bill ranges between below $10 to almost $30 per month.

Here are the water heater electricity bill winners and losers:

• You will pay, on average, the highest electric water heating bill in Delaware ($29.40 per month; combination of high average kWh usage and high electricity prices), followed by Alabama ($29.27 per month) and Maryland ($28.85 per month).
• You will pay, on average, the lowest electric water heating bill in Utah ($7.44 per month; combination of low average kWh usage and low electricity prices), followed by Idaho ($7.61 per month) and Wyoming ($8.13 per month).

---

Here you have it. The water heating kWh use ranges between 70 and 200 kWh per month; this cost anywhere from $7 to almost $30 per month, on average.

We hope that this statistical data analysis on the electric water heating kWh usage and cost gives you a variable insight into what normal kWh usage and cost looks like in your state.

If you have any questions about your specific situation, or would like to share how much you pay for electric water heating, you can use the comments below and we will help you out. If you need some suggestions on tankless units, you can check the best electric tankless water heater units here.