calculation help

hi guys its my first time growing i am currently running a 400watt hps im pretty usless with maths and would some one be able to help me figure out the running costs ive looked at tha how to calculate but its all gobbledegoop to me.
heres some figures 6.750 pence per kilowatt hour not sure what else i need to be doing numbers and me dont mix lol
thanks in advance

 

any one at all i dont want to go set this up and get busted for my bill please help?

 

Call your local police station and ask if any of them had a hankerin' for math in high school.

 

no dont think thats wise lol

 

google it?

 

http://www.advancednutrients.com/conversion_tools/powercost_tool/powercost.html


Per Month $21.60

 

whats that mean orison

 

The Cost to Run a Lighting System
To get the operating cost per hour for a light, take the lights combined wattage, and divide it by 1000 to get the kilowatts used. Then multiply that number by the amount your electric company charges per kilowatt hour. HID lights will use the number of watts it emits per hour, ie; 600w system will use 600 watts per hour (regardless of spectrum).
so if im running a 400watt @ 6.750 per khour it will be 4.05045 is that per hour or for the total i have no idea what a kilowatt hour is is it just a hour or more?its all gobbledgoop lol

 

i think thats two hours

 

thanks orison iots a lot better than i came up with lol it was £200 od lol

 

I just gave you the answer on average.. but its really close.

 

well least it wont cost me what i thought >>>>>>runs to finnish of the room

 

Dude, a 400 watt HPS with only look like a computer running full time. I would not worry about it.