To Find  Direct Current  Alternating Current  

Single Phase  TwoPhase* FourWire  Three Phase  
Amperes when Horsepower is known  HP x 746
E x EFF 
HP x 746
E x EFF x PF x 2 
HP x 746
2 x E x EFF x PF 
HP x 746
E x EFF x PF x 1.73 
Amperes when Kilowatts are known  KW x 1000
E 
KW x 1000
E x PF 
KW x 1000
2 x E x PF 
KW x 1000
E x PF x 1.73 
Amperes when "KVA" is known  KVA x 1000
E 
KVA x 1000

KVA x 1000
E x 1.73 

Kilowatts  E x I
1000 
E x I x PF
1000 
I x E x 2 x PF
1000 
E x I x 1.73 x PF
1000 
KilovoltAmperes "KVA"   I x E
1000 
I x E x 2
1000 
E x I x 1.73
1000 

Horsepower (Output)  E x I x EFF
746 
E x I x EFF x PF
746 
I x E x 2 x EFF x PF
746 
E x I x EFF x PF x 1.73
746 
E = Voltage
I = Amps
PF = Power Factor
EFF = Efficiency
HP = HorsepowerSingle phase formulas do not use (2 or 1.73)
Note: Direct current formulas do not use (PF, 2, or 1.73)