How much does it cost to run a desktop computer?
A desktop computer drawing 200 watts, used 6 hours a day, uses about 1.20 kWh per day and costs about $0.23 per day, $7.09 per month, and $85.02 per year at the US average residential rate of 19.4¢/kWh. Enter your own wattage, hours, and state below for an exact figure.
Estimates only — based on typical wattages and average state rates, not your actual bill.
What drives the cost
A typical office-style desktop draws around 200 watts including its monitor, though light-duty machines can be well under 100. Unlike laptops, desktops rarely throttle aggressively when idle, so leaving one running all day costs meaningfully more than a laptop doing the same work.
Cost at different daily usage
Same desktop computer at 200 watts, run for different amounts of time, at 19.4¢/kWh.
| Usage | kWh/day | Per day | Per month | Per year |
|---|---|---|---|---|
| 3 h/day | 0.60 kWh | $0.12 | $3.55 | $42.51 |
| 6 h/day | 1.20 kWh | $0.23 | $7.09 | $85.02 |
| 9 h/day | 1.80 kWh | $0.35 | $10.64 | $127.52 |
| 12 h/day | 2.40 kWh | $0.47 | $14.18 | $170.03 |
Cost by model power draw
Not all models are equal. At 6 h/day, here is what the range costs.
| Model | Power | kWh/day | Per day | Per month |
|---|---|---|---|---|
| Low-draw model | 80 W | 0.48 kWh | $0.09 | $2.84 |
| Typical | 200 W | 1.20 kWh | $0.23 | $7.09 |
| High-draw model | 400 W | 2.40 kWh | $0.47 | $14.18 |
Cost by state
A desktop computer at 200 W for 6 h/day, priced at each state's average residential rate.
| State | Rate | Per day | Per month | Per year |
|---|---|---|---|---|
| Alabama | 16.8¢ | $0.20 | $6.13 | $73.45 |
| Alaska | 28.2¢ | $0.34 | $10.31 | $123.65 |
| Arizona | 15.2¢ | $0.18 | $5.56 | $66.71 |
| Arkansas | 14.4¢ | $0.17 | $5.25 | $62.90 |
| California | 33.2¢ | $0.40 | $12.15 | $145.64 |
| Colorado | 16.2¢ | $0.19 | $5.90 | $70.78 |
| Connecticut | 27.4¢ | $0.33 | $10.00 | $119.88 |
| Delaware | 19.4¢ | $0.23 | $7.08 | $84.88 |
| District of Columbia | 25.4¢ | $0.30 | $9.28 | $111.25 |
| Florida | 15.2¢ | $0.18 | $5.54 | $66.44 |
| Georgia | 15.8¢ | $0.19 | $5.79 | $69.38 |
| Hawaii | 52.0¢ | $0.62 | $18.99 | $227.76 |
| Idaho | 12.3¢ | $0.15 | $4.51 | $54.09 |
| Illinois | 23.9¢ | $0.29 | $8.71 | $104.46 |
| Indiana | 18.1¢ | $0.22 | $6.63 | $79.50 |
| Iowa | 14.1¢ | $0.17 | $5.17 | $61.93 |
| Kansas | 15.1¢ | $0.18 | $5.53 | $66.27 |
| Kentucky | 15.0¢ | $0.18 | $5.47 | $65.61 |
| Louisiana | 14.2¢ | $0.17 | $5.17 | $61.98 |
| Maine | 28.6¢ | $0.34 | $10.46 | $125.40 |
| Maryland | 21.8¢ | $0.26 | $7.95 | $95.35 |
| Massachusetts | 28.8¢ | $0.35 | $10.53 | $126.23 |
| Michigan | 22.0¢ | $0.26 | $8.04 | $96.40 |
| Minnesota | 16.9¢ | $0.20 | $6.19 | $74.24 |
| Mississippi | 16.2¢ | $0.19 | $5.90 | $70.78 |
| Missouri | 13.7¢ | $0.16 | $5.00 | $59.92 |
| Montana | 14.7¢ | $0.18 | $5.36 | $64.25 |
| Nebraska | 13.6¢ | $0.16 | $4.96 | $59.52 |
| Nevada | 13.6¢ | $0.16 | $4.97 | $59.57 |
| New Hampshire | 27.3¢ | $0.33 | $9.98 | $119.71 |
| New Jersey | 23.3¢ | $0.28 | $8.50 | $101.92 |
| New Mexico | 14.1¢ | $0.17 | $5.16 | $61.85 |
| New York | 29.9¢ | $0.36 | $10.93 | $131.09 |
| North Carolina | 15.1¢ | $0.18 | $5.51 | $66.09 |
| North Dakota | 13.6¢ | $0.16 | $4.97 | $59.61 |
| Ohio | 19.5¢ | $0.23 | $7.13 | $85.50 |
| Oklahoma | 13.4¢ | $0.16 | $4.89 | $58.60 |
| Oregon | 16.3¢ | $0.20 | $5.94 | $71.26 |
| Pennsylvania | 21.6¢ | $0.26 | $7.87 | $94.39 |
| Rhode Island | 29.5¢ | $0.35 | $10.76 | $129.03 |
| South Carolina | 16.2¢ | $0.19 | $5.91 | $70.87 |
| South Dakota | 15.7¢ | $0.19 | $5.75 | $68.90 |
| Tennessee | 14.5¢ | $0.17 | $5.29 | $63.38 |
| Texas | 16.4¢ | $0.20 | $6.01 | $72.01 |
| Utah | 13.0¢ | $0.16 | $4.73 | $56.76 |
| Vermont | 24.9¢ | $0.30 | $9.09 | $109.02 |
| Virginia | 17.6¢ | $0.21 | $6.43 | $77.13 |
| Washington | 14.9¢ | $0.18 | $5.46 | $65.48 |
| West Virginia | 16.8¢ | $0.20 | $6.14 | $73.58 |
| Wisconsin | 19.7¢ | $0.24 | $7.21 | $86.46 |
| Wyoming | 14.8¢ | $0.18 | $5.41 | $64.82 |
How to cut the cost
- Set sleep to trigger after 15-30 minutes of inactivity rather than never.
- Power off overnight; modern machines boot quickly enough that leaving them on isn't worth it.
- Switch monitors off separately if they don't sleep reliably.
- Consider a laptop or mini PC for light workloads — the efficiency difference is large.
Compare with related appliances
Monthly cost at typical usage and 19.4¢/kWh.
Questions
Is it cheaper to leave a computer on or turn it off?
Turning it off is cheaper. The old argument about startup surge damaging components no longer applies to modern hardware.
How do you calculate what a desktop computer costs to run?
Multiply its wattage by the hours it runs per day, divide by 1,000 to get kilowatt-hours, then multiply by your electricity rate. For a desktop computer: 200 W × 6 h ÷ 1,000 = 1.20 kWh per day, which at 19.4¢/kWh is $0.23 per day.
How many watts does a desktop computer use?
Typically 200 watts, with most models falling between 80 and 400 watts. The label on the appliance or its power supply gives the figure for your specific unit.