# How can I tell how much power my computer is using? **URL:** \ **Category:** Factual Questions\ **Created:** [January 12, 2006, 11:08am UTC](https://boards.straightdope.com/t/how-can-i-tell-how-much-power-my-computer-is-using/339645 "2006-01-12T11:08:31Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![FlyingRamenMonster](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@FlyingRamenMonster](https://boards.straightdope.com/u/FlyingRamenMonster)\ **Post date:** [January 12, 2006, 11:08am UTC](https://boards.straightdope.com/t/how-can-i-tell-how-much-power-my-computer-is-using/339645/1 "2006-01-12T11:08:31Z")
Since it looks like I might finally be getting a job (I’ve been applying to like every freaking job for over a year now but NONE OF THEM WANT ME and they’re just burger places and stuff, not exactly genius-level stuff here) I’ve been thinking about paying my parents for board. They don’t like this idea but I do. Since my computer is on for most of the day I figured I might want to work out how much power I’m using. Is there like something I can plug into the circuit for a day and see how much charge has passed through? Or do I have to estimate the number of hours it’s on each day and use an ammeter or something? Where, for that matter, am I supposed to find an ammeter? Yeah, I hear you thinking _honestly_, **FRM** , you don’t need to be this anal about your board. And you’re right, I don’t. I confess that this is just an excuse to find out the answer to a question that has bugged me for years 😃 ---
**Author:** ![Omniscient](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/omniscient/32/3290_2.png) [@Omniscient](https://boards.straightdope.com/u/Omniscient)\ **Post date:** [January 12, 2006, 11:15am UTC](https://boards.straightdope.com/t/how-can-i-tell-how-much-power-my-computer-is-using/339645/2 "2006-01-12T11:15:31Z")
Well, your monitor and PC’s power supply have wattage ratings which indicate maximum power consumption. From that you could measure the Watt-hours you’d consume in the most extreme case pretty simply. As for measuring actual throughput, I don’t know. You’d probably have to check Radio Shack. ---
**Author:** ![mks57](https://avatars.discourse-cdn.com/v4/letter/m/b9bd4f/32.png) [@mks57](https://boards.straightdope.com/u/mks57)\ **Post date:** [January 12, 2006, 12:56pm UTC](https://boards.straightdope.com/t/how-can-i-tell-how-much-power-my-computer-is-using/339645/3 "2006-01-12T12:56:10Z")
You want something like [this meter](http://www.p3international.com/products/special/P4400/P4400-CE.html). ---
**Author:** ![Otanx](https://avatars.discourse-cdn.com/v4/letter/o/c5a1d2/32.png) [@Otanx](https://boards.straightdope.com/u/Otanx)\ **Post date:** [January 12, 2006, 1:14pm UTC](https://boards.straightdope.com/t/how-can-i-tell-how-much-power-my-computer-is-using/339645/4 "2006-01-12T13:14:03Z")
I was hoping that I would be the first to post about the Kill a Watt. Here is a link where you can buy one. [Kill-a-Watt](http://www.thinkgeek.com/gadgets/electronic/7657/) -Otanx ---
**Author:** ![Shalmanese](https://avatars.discourse-cdn.com/v4/letter/s/45deac/32.png) [@Shalmanese](https://boards.straightdope.com/u/Shalmanese)\ **Post date:** [January 12, 2006, 2:20pm UTC](https://boards.straightdope.com/t/how-can-i-tell-how-much-power-my-computer-is-using/339645/5 "2006-01-12T14:20:40Z")
Most computers use somewhere around 100W a day with another 30W for LCD Monitors or 100W for CRTs. Assuming 200W, 8 hours a day, that works to around 1.6kW/hr which, at roughly 10c per kW/hr means your using 16 cents a day.