WattCost

Data through April 2026

Cost to run · Illinois · 20.5¢/kWh residential average

How much does it cost to run a room air conditioner in Illinois?

$109/yr · median certified model

Illinois's residential rate of 20.5¢/kWh tracks the national average (18.8¢) closely, so national cost figures translate almost directly: a median certified room air conditioner runs about $109 a year here.

In the national ranking, Illinois lands at 36 of 51 for what a room air conditioner costs to run. Model choice matters as much as geography: at Illinois rates the most efficient certified model (TCL T05WV9M) costs $56 a year while the most power-hungry (Friedrich KCVL36B30A) costs $429 — a spread of $373 every year. For reference, the national extremes are North Dakota (12.3¢/kWh) and Hawaii (46.6¢/kWh); the same median room air conditioner would cost $66 and $248 a year there.

Illinois
$109
US average
$100
North Dakota
$66
Hawaii
$248
Median certified room air conditioner (532 kWh/yr) per year, at each rate

The cheapest room air conditioners to run at Illinois rates

Top 10 by certified kWh, priced at 20.5¢/kWh
#ModelkWh/yr$/yr in IL
1TCL T05WV9M274$56
2TCL T05WV9MB274$56
3TCL T05WV9R274$56
4TCL T05WV9RB274$56
5TCL W5WC72274$56
6TCL W5WC72-B274$56
7TCL W5WC72M274$56
8TCL W5WC72M-B274$56
9LG LW6023IVSMmost efficient290$59
10Midea MAW06U1QWTmost efficient298$61

Price any model at Illinois rates

Your rate, your numbers

Per day
30¢
Per month
$9.08
Per year
$109

532 kWh/yr × 20.5¢/kWh = $109/yr

Prefilled with the median certified room air conditioner (532 kWh/yr). Every model page on this site carries its exact certified figure.

Questions, answered with the data

How much does it cost to run a room air conditioner in Illinois?
About $109 a year for the median ENERGY STAR certified room air conditioner, at Illinois's average residential rate of 20.5¢/kWh — that's $9.07 a month.
Is electricity expensive in Illinois?
Illinois's residential average of 20.5¢/kWh is 9% above the U.S. average of 18.8¢/kWh, ranking 36 of 51 jurisdictions (1 = cheapest).
What's the cheapest room air conditioner to run in Illinois?
Among currently certified models, the TCL T05WV9M costs the least at about $56 a year at Illinois rates (274 kWh/yr).
How does Illinois compare with other states?
The same median room air conditioner costs $66 a year in North Dakota (the cheapest state) and $248 in Hawaii (the priciest). Illinois sits at $109.

Keep digging

Rate source: US EIA, average residential price of electricity, see methodology.