Yes, 17w

Monitors typically have 3 power levels:

On -- you're looking at one. Standby -- screen is black, but the electronics are active. Sleep -- circuits are off except for a small one to monitor the line to the computer Off -- it turns into a fancy cookie tray.

I'm using a Dell U2412 21" monitor. I went to their web site and looked up the specs.

Max 72 watts, Typical 38 watts, Sleep/Standby Under .5 watts.

Look up your monitor model online to check. Your mileage may vary.

Given that the average North American household uses about 1000 kWh/month, if your monitor were in actual use all month (720 hours) at 40 watts it would use 28800 watt hours or 28 kWh. About $3 to $5 depending on your power rates. Most monitors are set to go to sleep after a few minutes of inattention. You are talking about cents per month.

In passing: Turning your computer off is a bad idea too.

My computer right now in active use (Mac Pro, 4 processor 6 drives, 3 monitors) is drawing under 200 watts. Half that is the monitors, half the computer. If it doesn't sleep at all when I'm away it uses 2.4 kWh/day -- about 40 cents at my power rates. That's $240 per year.

Ouch! you say. But the flip side is my computers don't break down. When I was sysadmin for a university math department, I averaged three disk failures per year -- out of 300 computers. With the standards of the time I should have had 15 failures per year. How much is your time worth?

Without knowing the make and model number of the power supply keep in mind just because it says 600 watts doesn't mean it can deliver that. For the Kill A Watt it does fairly well but can't react fast enough to read short power spikes. The PSU power needed is almost all gated by the graphics card. For that, here is a handy chart: http://www.realhardtechx.com/index_archivos/Page362.htm What is the make/model of your psu? 600w does not tell it all. For a GPU, the 12v portion is what the gpu and cpu will use. 600w is an indicator that you might have an older psu of perhaps questionable quality. You are likely looking at a psu upgrade. I have a smaller build (micro atx/mini itx range) so I have a smaller form PSU. It's an Corsair SF Series 600w 80 plus gold PSU. Would this be viable? Programs like HWINFO don't log the mainboard power draw, for example. Like, HWINFO says my CPU uses 40W and my GPU 202W after tuning, while gaming. That's 242W. However, looking at the watt meter I have, my system actually uses around 320W. The remaining 80W would therefore be what the rest of the system - mainboard, RAM, drives, peripherals - uses. Software isn't telling you any of this. Okay, thanks for the additional info. I'll keep that in mind.