How much does a desktop computer cost to run in South Carolina?
$4.54 a month
- A day of use
- $0.15
- An hour of running
- $0.02
- A year
- $54.49
120 W, 8 hours a day (tower only, no monitor), at South Carolina’s average rate of 15.6¢ 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 | $0.57 | $6.81 |
| 2 hours a day | $0.04 | $1.14 | $13.62 |
| 4 hours a day | $0.07 | $2.27 | $27.24 |
| 8 hours a day typical | $0.15 | $4.54 | $54.49 |
| 24 hours a day | $0.45 | $13.62 | $163.46 |
A typical model draws about 120 W (Virginia Cooperative Extension).
South Carolina compared with other states
South Carolina’s residential rate is the 21st cheapest of 51 states and DC, 2.8¢ below the US average of 18.3¢ (−15%). South Carolina’s rate is up 0.8¢ from June 2025 (14.8¢, +5.1%).
A cheaper way to do the same job
- A laptop for the same hours would cost $1.89 a month, saving $2.65 a month and $31.78 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 South Carolina. A desktop computer at 120 W uses 0.120 kWh per hour, and at South Carolina’s average of 15.6¢ 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 $4.54 a month in South Carolina, or $54.49 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 $0.45 a day, or $13.62 over an average month in South Carolina.
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 $1.89 a month instead of $4.54, saving $2.65 in South Carolina.
Why does a desktop computer cost more or less to run in South Carolina than elsewhere?
South Carolina’s residential rate is the 21st cheapest of 51 states and DC, 2.8¢ below the US average of 18.3¢ (−15%). South Carolina’s rate is up 0.8¢ from June 2025 (14.8¢, +5.1%). 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.