How to calculate energy consumption?

energy consumption = Payroll check - (food+rent+beer+liquor+internet+trash+sewer+savings)

sorry, best I can do...

 

The easy way to do it is to get a meter that'll measure the current draw by the device. Otherwise, it's just going to depend on what you have installed in your PC. Most of my computers, even the ones with large power supplies, seldom draw over 100W total under a load. Most average 50-60W.

But even then it can be hard to calculate. My electric company (Socal Edison) have so many tiers of consumption, peak vs. non-peak, and so on - it's hard for me to know exactly what I'm paying per kilowatt hour anyway.

I'd just leave the thing on for a month and see what the difference in your bill is.

 

People usually recommend the Kill a Watt, so I will too: http://www.thinkgeek.com/gadgets/travelpower/7657/

That will give you an accurate measure of how much energy (kWh) your computer or other appliances use in a day (or week if you want to measure for that long).

Greg