Hello,
sorry that just isn't right I'm sure you meant ;
P=I*E
Or rearranged :
Watts = Amps*Voltage
Amps = Watts / Voltage
Voltage = Amps / Watts
etc..
But even that isn't fully all of the story if you are talking AC power
and Inductive loads.....
then you deal with Impedance and other fun things (power factor),
long story short ... it's complex.
Hth,
M.E.Farmer