The computation is just an example not the exact value of how many kw-hr and cost amount used on every household. How to know your monthly kw-hr consumption, by reading it your elec. meter.

Here's what you should do.... start of the month on any given cut-off day by your elec. company. Check your meter number, say its 5,090 then at end of month (given day) check it again say its 6,937= 1,847 kw an hour used.
So the diff. is 1,847 kw-hr. x cost per kw-hr. = (?). That is the cost of electricty in a month not including tax and misc. fee.