🔌 PC Power Cost Calculator

Enter how many watts your computer draws, how many hours a day it runs and what you pay per kilowatt-hour. The result is in the same currency as your price.

Power draw (watts)Best measured with a plug-in power meter.

Hours per day

Electricity price per kWhFrom your electricity bill, all taxes included.

Cost per year

Cost per month

Energy per year

How it is calculated

Watts times hours gives watt-hours; divide by 1,000 for kilowatt-hours, the unit on your bill. A machine drawing 300 W for four hours a day uses 1.2 kWh a day, or 438 kWh a year.

Finding the right wattage

The number on the power supply is its maximum, not what the computer uses. Real draw varies a lot: a laptop doing office work may use a few tens of watts, while a gaming PC under heavy load can draw several hundred. A plug-in power meter shows the real figure; measure both idle and under your normal load, and use an average.

Limits

The monitor, speakers and other devices are not included unless you add their watts. Sleep and standby still use a little power, which a full-day estimate would need to include.

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