How much does a desktop computer cost to run in Illinois?
$5.81 a month
- A day of use
- $0.19
- An hour of running
- $0.02
- A year
- $69.69
120 W, 8 hours a day (tower only, no monitor), at Illinois’s average rate of 19.9¢ per kWh (EIA, June 2026). How we calculate this
Change the watts, hours or rate
What it costs at other usage levels
| Use | A day | A month | A year |
|---|---|---|---|
| 1 hour a day | $0.02 | $0.73 | $8.71 |
| 2 hours a day | $0.05 | $1.45 | $17.42 |
| 4 hours a day | $0.10 | $2.90 | $34.85 |
| 8 hours a day typical | $0.19 | $5.81 | $69.69 |
| 24 hours a day | $0.57 | $17.42 | $209.08 |
A typical model draws about 120 W (Virginia Cooperative Extension).
Illinois compared with other states
Illinois’s residential rate is the 16th most expensive of 51 states and DC, 1.6¢ above the US average of 18.3¢ (+8%). Illinois’s rate is up 1.6¢ from June 2025 (18.3¢, +8.7%).
A cheaper way to do the same job
- A laptop for the same hours would cost $2.42 a month, saving $3.39 a month and $40.66 a year.
Ways to spend less
- Set it to sleep after 15 minutes idle.
- Shut it down at night instead of leaving it on.
- For email and browsing, a laptop does the same job on much less power.
Questions
How much does it cost to run a desktop computer per hour?
About $0.02 an hour in Illinois. A desktop computer at 120 W uses 0.120 kWh per hour, and at Illinois’s average of 19.9¢ per kWh that comes to $0.02.
How much does a desktop computer add to your electric bill?
Used 8 hours a day (tower only, no monitor), about $5.81 a month in Illinois, or $69.69 a year.
How much does it cost to run a desktop computer 24 hours a day?
Running nonstop, a desktop computer would use 2.88 kWh a day and cost $0.57 a day, or $17.42 over an average month in Illinois.
How many watts does a desktop computer use?
A typical model draws about 120 W (Virginia Cooperative Extension). Check the label on yours: cost scales directly with watts, so a 20% lower wattage means a 20% lower bill.
Is it cheaper to run a desktop computer or a laptop?
Using a laptop for the same hours instead would cost about $2.42 a month instead of $5.81, saving $3.39 in Illinois.
Why does a desktop computer cost more or less to run in Illinois than elsewhere?
Illinois’s residential rate is the 16th most expensive of 51 states and DC, 1.6¢ above the US average of 18.3¢ (+8%). Illinois’s rate is up 1.6¢ from June 2025 (18.3¢, +8.7%). The appliance uses the same energy everywhere; only the price per kWh changes.
Sources
- Virginia Cooperative Extension: Estimating appliance and home electronic energy use (reproduces U.S. Department of Energy sample wattages)
- Penn State EGEE 102: Typical range of power consumption (wattage)
- U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A: average price of electricity to ultimate customers, residential, June 2026 Figures transcribed from republications of this table on September 26, 2026; pending direct verification from the EIA API.
- Carrier page: June 2026 residential average price, citing EIA Electric Power Monthly Table 5.6.A
Usage assumptions (hours a day, season) are ours and listed on the methodology page. Found an error? Tell us.