PC Electricity Cost Calculator - Free Online Tool

Estimate gaming and idle PC power costs.

About this tool

Estimate PC energy use and electricity cost by separating gaming power and hours from idle power and hours. The calculator reports gaming, idle, and combined kWh for the selected number of days, then applies your price per kWh.

How it works

  1. Enter the PC's representative whole-system power draw at the wall while gaming and while idle, in watts (W).
  2. Enter hours per day for each state; gaming and idle hours must not overlap and together cannot exceed 24.
  3. Enter the number of days, choose a currency, and enter your local price per kWh; then review the separate energy totals and combined cost.

Example use cases

  • Gaming and idle month: At 300 W for 3 gaming hours and 60 W for 5 idle hours each day, the PC uses 1.2 kWh per day. Over 30 days that is 36 kWh, or 7.20 currency units at 0.20 per kWh.
  • Compare usage patterns: Keep the wall-watt readings and per-kWh price the same, then compare different daily gaming and idle hours to see how schedule changes affect the estimate.

Frequently asked questions

Can gaming and idle hours add up to more than 24?

No. These states represent mutually exclusive time in a day, so their combined hours must be 24 or less. The calculator treats all remaining hours as zero PC use.

Can I use the wattage printed on my power supply?

A PSU's wattage rating describes capacity, not the power the PC is drawing. Use measured whole-system wall power or a suitable estimate for each state; the result depends on those inputs.