What Is the Average Electric and Gas Bill in Illinois?

Key Points of This Article:

• The average combined electric and gas bill in Illinois is about $231 per month, with electricity averaging around $138 per month (755 kWh at $0.1831/kWh) and natural gas averaging about $93 per month (8.8 MCF at $10.56 per MCF).
• Where you live matters, as major Illinois cities like Chicago, Aurora, Joliet, and Rockford average around $110 per month for electricity, while Naperville tends to be slightly lower due to newer, more energy‑efficient homes.
• Illinois homeowners can influence their energy costs by choosing a supplier and plan type, since the state’s deregulated energy market allows residents to select fixed‑rate, variable‑rate, unlimited, or earth‑friendly energy plans to better control monthly costs.

What Is the Average Electric Bill in Illinois? 

The average electric bill in Illinois is about $138.24 per month. We came to this estimate based on typical household electricity usage of 755 kilowatt-hours per month and the average residential electricity rate of 18.31 cents per kWh as of November 2025, according to the U.S. Energy Information Administration. 

To calculate it, we multiplied 755 kWh by $0.1831 per kWh, which equals $138.24 per month. 

It is important to understand that this number represents a statewide average across thousands of households, and this is just an estimated electricity bill. Some homes will use far less than 755 kWh per month, while others will use much more, which means your actual bill might be higher than our estimate.  

The average simply gives you a general reference point for what many Illinois households consume over the course of a year. 

This figure also reflects annualized usage, not just one season. Monthly bills can move above or below this level depending on the time of year. 

Looking to get more specific estimate closer to your home size? You're in luck, we have that too!  Let's look at the average electric bill in Illinois across different household sizes: 

Let's break down what this chart means: We found that a single person living in a smaller home and using around 500 kWh per month may average about $91.55. This usually covers basic lighting, refrigeration, cooking, charging devices, and moderate heating or cooling. If the person works outside the home most of the day, usage may stay steady and predictable. 

A four-person household using about 755 kWh per month would average around $138.24. In this setting, electricity use increases because of multiple devices running at once, frequent laundry loads, regular cooking, and longer air conditioning cycles during summer. With more activity in the home, usage naturally rises. 

In a larger or multi-generational household using closer to 1,200 kWh per month, the average electricity bill in Illinois climbs to about $219.72. More occupied rooms mean more lighting, more electronics, and more heating or cooling throughout the day. Larger homes also require more energy to maintain consistent indoor temperatures across multiple floors or living areas. 

These examples show that the average electric bill in Illinois depends heavily on household size, daily routines, and how much of the home is actively used. 

The biggest driver in an increased electricity bill is usage. More people in the home typically means more lighting, more laundry, more cooking, more electronics, and longer air conditioning run times, leading to a higher bill.  

Now that we've looked at the statewide averages, let's compare them to what Santanna customers pay based on the same household types: 

Comparing our Santanna customer data to the statewide average electricity bill in Illinois, across every household type, Santanna customers pay noticeably less. For example, a single‑occupant home pays about 5.8% less per month with Santanna's average cost of $86.20 compared to the Illinois average of $91.55. 

A typical four‑person family under a Santanna energy plan in Illinois sees around $8 less on their electricity bill compared to statewide averages.  

Average Electricity Bill in the Most Major Illinois Cities 

If you're looking to make the move to Illinois and are wondering what moving to some of the major cities in the state can cost you in terms of electricity, we've crunched the numbers for you. 

Let's take a look at the average electricity bill in Illinois' most major cities: 

We found that the average electricity rate as of March 2026 in Chicago, Aurora, Rockford, and Joliet, Illinois, totals 14.66 cents per kilowatt-hour. That means at a monthly electricity usage of 775 kilowatt-hours per month, these major Illinois cities can expect an average electricity bill of $110 per month, while Naperville falls a few dollars less at $101 per month. 

Average Electricity Bill in Chicago Based on Different Energy Usage    

If you're wondering what the average electricity bill is in Chicago, can expect an average electricity bill of $110.68 at 755 kilowatt-hours of monthly electricity usage at the rate of 14.66 cents per kWh.  

But electricity costs in Chicago shift depending on how much energy your home uses each month. Chicago homes with a higher energy use of around 1,500 kWh can bring the monthly bill to over $200+.

Average Electric Bill in Aurora, IL, Rockford, IL and Joliet, IL 

Illinois cities like Aurora, Rockford, and Joliet are among the most populous in the state. 

Because they share similar residential electricity rates, their average monthly electric bills closely mirror each other. While each city has unique housing styles, population densities, and weather patterns, they all follow the same general rate structure of 14.66 cents per kilowatt‑hour. 

Aurora, Rockford, and Joliet residents can expect a similar average electricity bill of $110.68, just like in Chicago. 

Average Electricity Bill in Naperville 

Naperville stands out from other major Illinois cities in population and its suburban layout. Naperville has a lower residential electricity rate, which helps keep monthly electric bills slightly more affordable compared to Chicago, Aurora, Rockford, and Joliet. 

Homeowners living in Naperville can expect an average electricity bill of $101.17 at 755 kilowatt-hours of monthly electricity usage at the rate of 13.40 cents per kWh. 

Many homes in Naperville are relatively modern or recently upgraded, which often means better insulation, newer HVAC systems, and more energy‑efficient appliances, leading to lower electricity bills. 

What Is the Average Gas Bill in Illinois? 

The average gas bill in Illinois is about $92.93 per month. 

We arrived at our estimate based on typical household natural gas usage of 91 therms per month, which equals about 8.8 MCF, and the November 2025 average Illinois residential natural gas rate of $10.56 per MCF, according to the U.S. Energy Information Administration. 

To calculate it, we multiplied 8.8 MCF by $10.56 per MCF, which equals $92.93 per month. 

Keep in mind that our estimate represents an annual average. That means some months will be much lower and others much higher.  

According to the Energy Information Administration, almost three-quarters of Illinois residents use natural gas for heating their homes. Natural gas usage increases significantly between December and March, while during the summer months, usage drops and bills become much lower. 

For homeowners, this figure serves as a general reference point, but your actual bill will depend on the size of your home, the efficiency of your furnace, and how much heating your household requires during colder months. 

Depending on your home size and how many occupants are in your home, your average gas bill in Illinois can range from $60-$147 per month. 

Here's an example of how much your gas bill can fluctuate from month to month: 

A single person living in a smaller home and using about 6 MCF per month may average around $63.36. In this situation, gas is typically used for heating a smaller space, hot water, and cooking. If the home is well-insulated, usage may stay relatively moderate, although winter bills can still increase during colder periods. 

A four-person household using around 8.8 MCF per month would average about $92.93. With more occupants comes more hot water usage for showers, laundry, and dishwashing, along with longer furnace run times during the heating season. In Illinois, where winters can stretch for several months, heating becomes the largest driver of natural gas costs for a typical family home. 

In a larger or multi-generational household using closer to 14 MCF per month, the average monthly gas bill may reach about $147.84. Larger homes require more energy to heat multiple rooms and floors, and additional occupants increase daily hot water demand. During especially cold winters, bills in homes of this size can rise well above the yearly average.  

Looking at your total usage over the year, rather than focusing on one high winter month, provides a clearer and more balanced understanding of what your household spends on natural gas in Illinois.

We've crunched the numbers from our own customer data and found that an average Santanna Energy Services customer's natural gas bill can range from $87-$203 per month, depending on home size and occupancy. 

Why Natural Gas Bills in Illinois Change Throughout the Year 

Gas bills in Illinois follow a winter-driven pattern. Natural gas is used mostly for heating and hot water, which makes cold weather the biggest factor. Here are the most common reasons why Illinois natural gas bills change throughout the year: 

1. Cold temperatures increase furnace runtime: Furnaces work harder and longer when outdoor temperatures drop. This is the main reason gas usage spikes from late fall through early spring. 
2. Longer heating seasons in Illinois raise annual consumption: Illinois winters often stretch across several months, which increases total yearly therm or MCF usage compared to warmer states. 
3. Larger homes need more heating energy: Heating more square footage requires more natural gas, especially in homes with multiple floors or finished basements. 
4. More occupants increase hot water usage: Showers, laundry, and dishwashing all use hot water, which is commonly heated by natural gas in Illinois homes. 
5. Insulation and air sealing affect heating demand: Homes that lose heat quickly require furnaces to run more often, which increases total gas consumption. 

Why Electricity Bills in Illinois Change Throughout the Year 

Electric bills in Illinois tend to follow a summer-driven pattern. While usage continues year-round, electricity spikes are usually tied to cooling demand and daily household activity. Here are the most common reasons why Illinois electricity bills change throughout the year: 

1. Summer air conditioning increases electric usage: Air conditioners use more electricity than almost any other appliance in the home. During hot and humid Illinois summers, systems run longer to maintain comfort, which pushes up monthly kWh usage. 
2. Longer daylight hours increase appliance and electronics use: Summer often means more activity at home, including fans, televisions, computers, and kitchen appliances running more frequently. 
3. Electric heating dramatically changes winter bills for some homes: Homes that rely on electric heating (only around 10% of Illinois residents do, according to the E.I.A) instead of natural gas can see large spikes in winter electric usage because electric resistance heat consumes a high amount of power. 
4. Larger homes require more cooling power: Cooling a two-story or larger home takes more energy than cooling a small condo or apartment, even at the same thermostat setting. 
5. Appliance efficiency affects steady monthly usage: Older refrigerators, freezers, or window AC units can quietly increase electric consumption throughout the year. 

How Illinois Electricity Bills Compare to Other States 

Illinois electricity bills fall near the national middle range. At $138.24 per month for 755 kWh, Illinois is significantly lower than high-cost states. Hawaii at $301.17 is about 118% higher than Illinois, and California at $254.81 is about 84% higher for the same usage. 

Within the Midwest, Illinois is moderately priced. Michigan at $136.28 is about 1% lower than Illinois, while Ohio at $117.48 is about 15% lower, and Pennsylvania at $135.75 is about 2% lower for the same 755 kWh monthly usage in terms of an average electricity bill. 

Illinois is also higher than some of the lowest-cost states. Wyoming at $89.62 is about 35% lower than Illinois, and North Dakota at $90.07 is about 35% lower as well. 

Overall, Illinois electricity costs are moderate nationally and remain competitive within the Midwest, though slightly higher than some neighboring states. 

To make this comparison meaningful, we used the same average monthly usage for every state: 755 kilowatt-hours per month. That allows us to compare electric bills based only on the residential electricity rate in each state as of November 2025. 

How Illinois Natural Gas Bills Compare to Other States 

Within the Midwest, Illinois is very competitive. Michigan at $93.81 is about 1% higher than Illinois. Ohio at $117.30 is about 26% higher, and Pennsylvania at $134.73 is about 45% higher for the same 8.8 MCF monthly usage. 

Overall, Illinois natural gas rates are moderate nationally and remain competitively priced compared to several neighboring Midwest states. 

To make this comparison meaningful, we used the same average monthly usage for every state: 91 therms per month, which is about 8.8 MCF. This allows us to compare natural gas bills based only on the residential natural gas rate in each state as of November 2025. 

Why Your Illinois Energy Bill Is Higher Than Your Neighbor's 

It is common to compare bills with neighbors. But two homes on the same street can have very different energy costs. Even if you pay the same rate, your usage can vary for many practical reasons. 

Here are some of the biggest factors that affect your bill: 

Home Size 

A larger home requires more energy to heat and cool. More square footage means more air to condition and more rooms to light. 

Insulation Levels 

Homes with strong attic insulation and sealed walls retain heat in winter and keep cool air in during summer. Poor insulation forces your system to run longer. 

Heating Type: Gas vs. Electric 

Electric resistance heating typically costs more to operate than natural gas heating in Illinois. Two similar homes can have very different winter bills depending on fuel type. 

Age of HVAC System 

Older furnaces and air conditioners are less efficient. They use more energy to deliver the same comfort compared to newer, high-efficiency systems. 

Number of Occupants 

More people means more showers, more laundry, more cooking, more electronics, and longer heating or cooling cycles. 

Work-From-Home Households 

Homes occupied all day naturally use more electricity. Computers, lighting, climate control, and kitchen appliances run longer. 

Water Heater Type 

Electric water heaters often use more electricity than gas models. Hot water usage plays a steady role in monthly energy consumption. 

Air Leaks 

Drafts around doors, windows, and vents allow conditioned air to escape. Even small gaps can increase heating and cooling demand. 

Appliance Age 

Older refrigerators, freezers, dryers, and window AC units tend to consume more energy than modern ENERGY STAR-rated models. 

Two households can live side by side and have very different energy habits and home efficiency levels. That is why comparing total bills without understanding usage can be misleading. The more helpful comparison is how your current bill aligns with your home's size, systems, and lifestyle. 

How Choosing an Energy Supplier in Illinois Can Impact Your Bill 

Illinois lives in a deregulated energy market, giving residents the ability to choose their energy supplier and have greater control over the type of energy plan they select. While you can't change the utility company that delivers your energy, you can choose who supplies it, meaning you have control over the supply portion of your bill. 

Different suppliers may offer different plan structures giving you more choices for energy plans that better fit your lifestyle. 

 Some plans lock in the rate you pay per kilowatt-hour or therm for a specific contract term while others allow the rate to adjust with market conditions. Some may offer a flat-fee or usage-based options. The type of plan you choose can affect how stable or flexible your monthly supply costs feel, making for easier budgeting and more predictability in your monthly energy costs. Which is why partnering with the right energy supplier can make all the difference. Check out your energy plan options with Santanna Energy Services today! 

Best Energy Plans in Illinois  

Once you understand what the average electric and gas bill looks like in Illinois, the next step is thinking about how your plan structure fits your lifestyle. 

Not every household uses energy the same way. Some families want stability. Others prefer flexibility. The "best" energy plan in Illinois is not one-size-fits-all. It depends on how you use energy and how you prefer to manage your budget. Here are some of the best energy plans in Illinois: 

Unlimited Energy Plans 

An Unlimited Energy plan works differently. Instead of paying per unit for the supply portion, you pay one flat supply charge amount each month, no matter how much energy you use.* 

This can be helpful during high-usage seasons. When winter heating or summer air conditioning pushes usage higher than usual, the supply portion remains the same. 

For households that value predictability and want a consistent supply charge throughout the year, this structure can provide peace of mind. It can be especially appealing for larger families or homes with seasonal usage spikes. 

Santanna's Unlimited Energy plan also includes a community impact component. Each month, enrollments contribute to donations to Midwest charities.**This allows customers to support local causes while getting the energy they need. Double the good! 

Fixed-Rate Plans 

A fixed-rate plan means the rate you pay for electricity and natural gas supply stays the same for the length of your contract. With this plan, your total bill still varies based on usage. 

In a state like Illinois, where winters are cold and summers are humid, usage naturally rises during peak seasons. A fixed supply rate keeps that price steady even when demand increases statewide. This type of plan often works well for homeowners who prefer stability! 

Variable-Rate Plans 

A variable-rate plan means the rate you pay can change from month to month based on market conditions. 

During mild weather, rates may decrease but during peak demand months like January or July, rates may rise. That means the rate you pay can fluctuate even if your usage stays similar. Some homeowners are comfortable with that variability. Others prefer more stability, especially in a state with strong seasonal swings like Illinois. 

Understanding your comfort level with change is an important part of choosing among the best energy plans in Illinois. 

Earth-Friendly Energy Plans 

Some Illinois energy companies offer options that support renewable energy. For electricity, this may include Renewable Energy Credits, which help fund renewable generation sources such as wind and solar. For natural gas, some plans include carbon offset programs that help balance emissions associated with home energy use. 

Santanna offers both Earth-Friendly Electricity and Earth-Friendly Natural Gas plans for Illinois homeowners who want their energy supply choice to support environmental efforts. 

When Should You Be Concerned About a Sudden Spike on Your Electric or Gas Bill?  

Most increases in Illinois energy bills are seasonal. But a sudden spike that does not match the weather or your routine may need attention. Below are red flags of a sudden spike in your electric or gas bill: 

• A 25%-30% percent increase without a weather change: If temperatures were similar to last month or the same month last year, but your bill jumped sharply, the spike may not be seasonal and could point to a rate change or system issue. 

• A sharp increase in therms or kWh usage: If your usage suddenly rises and your daily habits have not changed, something in your home may be running longer than it should. 

• Your contract term has ended: If your energy contract expired and you did not renew or select a new plan, you can potentially be enrolled in a new plan structure that could increase your bill even if usage stayed the same. 

• An appliance or HVAC system running continuously: A furnace, air conditioner, water heater, or refrigerator that does not cycle off properly can quietly raise energy use. 

• Increased use of space heaters: Space heaters consume a large amount of electricity and can quickly raise your electric bill during colder months. 

• A water leak affecting your water heater: Constant hot water flow forces your water heater to run longer, increasing gas or electric usage. 

• Possible gas leak warning signs: A sulfur smell, hissing sound, dizziness, or nausea indoors is a safety concern. Leave the area and contact your utility immediately. 

• Estimated bill instead of actual meter reading: If your bill is based on an estimate, it may temporarily appear higher than your actual usage. 

• New equipment installed with incorrect settings: A thermostat or HVAC system set improperly can cause longer run times and unexpected increases. 

Being above the Illinois average does not automatically mean something is wrong. But if your bill rises and the reason is not clear, these checks help you sort out whether the spike is normal, explainable, or worth action. 

Smart Ways to Lower Your Electric and Gas Bill in Illinois Right Now 

If your energy bill feels higher than expected, there are steps you can take right away. Some changes reduce usage immediately. Others improve efficiency over time. The key is focusing on actions that match how homes in Illinois actually use energy. 

Below are realistic steps and why each one helps. 

Adjust your thermostat by a few degrees 

Lowering your thermostat slightly in winter or raising it slightly in summer reduces how long your HVAC system runs. Even a 2 to 3 degree adjustment can lower heating or cooling demand without making your home uncomfortable. 

Use a programmable or smart thermostat 

Setting your thermostat to adjust when you are sleeping or away prevents unnecessary heating or cooling. This reduces system run time and lowers overall usage. 

Seal air leaks around doors and windows 

Small drafts let heated or cooled air escape. Sealing gaps with weatherstripping or caulk keeps conditioned air inside and helps your system work less. 

Replace your HVAC air filter 

A dirty air filter restricts airflow and forces your furnace or air conditioner to work harder. A clean filter improves efficiency and reduces strain on the system. 

Lower your water heater temperature slightly 

Reducing the temperature setting decreases the energy required to heat water. Water heating is a steady contributor to both electric and gas bills. 

Run full loads of laundry and dishes 

Running full loads reduces the number of wash cycles, saving both water and the energy used to heat that water. 

Switch to LED light bulbs 

LED bulbs use 90% less electricity than older incandescent bulbs. Since lighting is used daily, the savings add up over time. 

Limit space heater use 

Electric space heaters use a large amount of power. Using them sparingly helps prevent sudden increases in electric usage. 

Open blinds during sunny winter days 

Sunlight provides natural warmth. Letting it in during colder months can slightly reduce how often your heating system runs. 

Close blinds during hot summer afternoons 

Blocking direct sunlight keeps indoor temperatures cooler and reduces the need for air conditioning. 

Check if your bill is estimated 

If your bill is based on an estimate instead of an actual meter reading, submitting an updated reading may correct temporary overcharges. 

Upgrade older appliances when possible 

Older appliances often use more energy than newer, ENERGY STAR-rated models. Replacing high-usage equipment can lower long-term costs. 

Review your supply rate and contract details 

Sometimes lowering your bill is not just about usage. Reviewing your supply rate ensures your plan aligns with your household's usage patterns and budgeting style. 

FAQs  

Is it normal for my Illinois gas bill to double in winter? 

Yes, it can be normal. Illinois winters are cold, and most homes use natural gas for heating. The U.S. Energy Information Administration reports that space heating is the largest energy expense in colder regions. When temperatures drop, furnace usage increases significantly, which raises therm consumption. 

Is Illinois considered a high-cost energy state? 

Illinois electricity rates are close to the national average. They are not among the highest in the country. States like Hawaii and California have significantly higher average residential electricity rates. 

Does switching suppliers affect reliability? 

No. Switching energy suppliers in Illinois does not affect reliability. Your local utility company, such as ComEd or Nicor Gas, continues to deliver electricity or natural gas, maintain infrastructure, and respond to outages. Suppliers only affect the supply portion of your bill, not delivery or service reliability. 

Understanding the average electric and gas bill in Illinois helps you see what is normal, what is seasonal, and what may need attention. When you understand how usage and rates work together, your bill becomes something you can manage instead of react to. 

For Midwest homeowners, where winters and summers both drive strong energy demand, clarity makes budgeting easier and reduces surprises. Long-term stability often comes from choosing a structure that aligns with how your home uses energy. 

If predictable supply charges and steady planning matter to you, Santanna's Unlimited Energy plan is one option designed to support that approach. It may be worth exploring if you prefer fewer surprises during high-usage months* and a simpler way to budget throughout the year. 

* Restrictions apply. Enrollment based upon program eligibility. Customers using more than 125% of normal monthly usage as determined by Santanna may be required to switch plans. 

**For every Unlimited Energy gas or electricity initial enrollment or renewal, Santanna Energy Services will contribute corporate donations to a nonprofit organization in the Midwest after 60 days of billed usage. Plans may vary. See plan details for eligibility and current charity donation promotions.