Gaming PC, mid-range (while gaming) costs about $6.64 a month ($79.68 a year) at the U.S. average of 18.19¢/kWh, using 400 W for 3 hours a day.
At 18.19¢/kWh — U.S. average, Jan–Aug 2026 (EIA).
| Period | kWh | Cost |
|---|---|---|
| Per hour of use | 0.4 | $0.07 |
| Per day | 1.2 | $0.22 |
| Per month | 36.5 | $6.64 |
| Per year | 438 | $79.68 |
| Where | ¢/kWh | Month | Year |
|---|---|---|---|
| U.S. | 18.19 | $6.64 | $79.68 |
| North Dakota (cheapest) | 12.46 | $4.55 | $54.58 |
| Hawaii (most expensive) | 46.41 | $16.94 | $203 |
| State | ¢/kWh | Per month | Per year |
|---|---|---|---|
| Hawaii | 46.41 | $16.94 | $203 |
| California | 32.58 | $11.89 | $143 |
| Maine | 30.23 | $11.04 | $132 |
| Massachusetts | 30.19 | $11.02 | $132 |
| U.S. average | 18.19 | $6.64 | $79.68 |
| Utah | 13.19 | $4.81 | $57.78 |
| Idaho | 13.02 | $4.75 | $57.03 |
| Nebraska | 12.92 | $4.72 | $56.60 |
| North Dakota | 12.46 | $4.55 | $54.58 |
400 W ÷ 1,000 = 0.4 kW. × 3 h = 1.2 kWh a day; × 30.42 days = 36.5 kWh a month; × 18.19¢ = $6.64.
Prices are EIA's average residential price for Jan–Aug 2026. Pick your state in the calculator for your local figure.
The full method, material data and tips are on the main electricity cost calculator page.