Estimate what a computer, NAS, or monitor adds to an electricity bill. Use the watts it draws while you use it, not the number printed on the power supply. A 750 W supply does not mean the PC uses 750 W.
PC electricity cost calculator
The result updates from the fields above. This form does not store the numbers you enter.
What the result means
The monthly figure is 30 days at the hours and watts you entered. The yearly figure uses 365 days. It is the energy charge only, at the price per kilowatt-hour you typed. Delivery fees, taxes, and a cheaper overnight rate are not included unless you already folded them into that price.
Formula and example
Cost = (watts ÷ 1000) × hours × days × price per kWh. A PC at 150 W for 8 hours, at $0.16 per kWh, uses 1.2 kWh a day. That is about $5.76 over 30 days and about $70.08 over 365 days. Add the monitor’s watts if you want the desk, not only the tower.
What this number cannot tell you
Idle, a game, and a video export are different loads. One watt figure is an average you choose. A plug-in meter is the accurate measurement. The calculator does not know your utility’s tiers.
Questions people ask
Should I use idle watts or load watts?
Use a blend that matches the day. Eight hours of a game at 300 W is not the same as eight hours of a browser at 40 W. If you know both, calculate them separately and add the costs.
Does sleep mode count?
Only if you include those hours at the watts the machine draws while asleep. A sleeping PC is often a few watts, not its working load.
Is a NAS worth adding?
Yes, if it runs all day. A 15 W NAS for 24 hours is 0.36 kWh a day, which is more than a short gaming session at a higher wattage.
