How to calculate amp load based totally on watts for 12v system?

[ramesh]

I am pasting this answer, but hoping someone will give better answer for you.
In a direct current, 1 amp at 110 volts equals 110 watts,
whereas 1 amp at 220 volts equals 220 watts.
but what could be 1 amp of 12volts in watts? I think 12 watts would be for 12volts.