1. Find the number of watts being output. In most cases, watts are measured in watts per hour or kilowatts per hour. If it is measured in watts per hour, multiply the number by 3,600
http://www.ehow.com/how_6038931_calculatebtuoutp...

The formula you are looking for is I = W/E.
http://wiki.answers.com/Q/How_many_amps_will_a_400...

They will be 450 amps drawn from 1500 watt car amplifier. ChaCha on.
http://www.chacha.com/question/howmanyampsared...

The Sony Xplod 1000 is rated at a 40 amp draw as specified by the manufacturer. Enjoy!
http://www.kgbanswers.com/whatisthecurrentdraw...
