Electricity use guide
How much does a desktop computer and monitor cost to run?
Using a planning draw of 250 watts for 5.6 hours a day, this example uses 1.40 kWh daily. At the June 2026 monthly average U.S. residential rate of $0.1834 per kWh, that is about $0.26 per day or $93.72 per year.
- Daily electricity
- 1.40 kWh
- Monthly cost
- $7.81
- Annual electricity
- 511.0 kWh
- Annual cost
- $93.72
Calculation for this example
250 W ÷ 1,000 × 5.6 hr/day × 365 days × $0.1834/kWh = $93.72/yearElectricity use in kilowatt-hours equals watts divided by 1,000, multiplied by runtime. Cost equals that energy use multiplied by the price per kWh.
What changes the actual cost?
- Actual draw can change with the model, power setting, workload, age, and standby behavior.
- For the closest estimate, use the wattage on the nameplate or manual and measure daily runtime over a typical week.
The example is a labeled planning estimate, not a specification for every model. Its national average rate includes fixed-charge and tax revenue; no separate fees are added. It is not the exact additional charge for using this appliance on your tariff.
Hourly, daily, and annual running costs
These fixed examples use residential electricity prices from the June 2026 monthly average, not your selected calculator rate. All longer periods assume the example schedule every day; seasonal equipment will differ. Values below one cent display as <$0.01.
| Period | Energy kWh | Cost $0.1834/kWh |
|---|---|---|
| One hour at stated power | 0.250 | $0.05 |
| Day at example schedule | 1.400 | $0.26 |
| Week (7 days) | 9.800 | $1.80 |
| Average month (365 ÷ 12 days) | 42.583 | $7.81 |
| Year (365 days) | 511.000 | $93.72 |
Compare state-average rates Virginia, Washington, California, and Hawaii
Scroll sideways to compare all rates. With the table focused, use Left and Right arrow keys.
| Period | Energy kWh | U.S. average $0.1834/kWh | Virginia $0.1722/kWh | Washington $0.1491/kWh | California $0.3474/kWh | Hawaii $0.5272/kWh |
|---|---|---|---|---|---|---|
| One hour at stated power | 0.250 | $0.05 | $0.04 | $0.04 | $0.09 | $0.13 |
| Day at example schedule | 1.400 | $0.26 | $0.24 | $0.21 | $0.49 | $0.74 |
| Week (7 days) | 9.800 | $1.80 | $1.69 | $1.46 | $3.40 | $5.17 |
| Average month (365 ÷ 12 days) | 42.583 | $7.81 | $7.33 | $6.35 | $14.79 | $22.45 |
| Year (365 days) | 511.000 | $93.72 | $87.99 | $76.19 | $177.52 | $269.40 |
Source: U.S. EIA residential electricity prices. These averages include fixed-charge and tax revenue, so they are not your utility’s marginal price for an additional kWh.
Get a result for your appliance
Enter the wattage from your appliance label, your typical schedule, and the electricity rate from your bill. The calculator shows daily and annual energy, cost, source details, and the arithmetic used.
Calculate your desktop computer and monitor cost