Electrical Formulas Posted on February 26, 2017 by Brandy McNeil To Find Direct Current Alternating Current Single Phase Two-Phase* Four-Wire 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 Kilovolt-Amperes "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 = Horsepower Note: Direct current formulas do not use (PF, 2, or 1.73) Single phase formulas do not use (2 or 1.73) Two phase-four wire formulas do not use (1.73) Three phase formulas do not use (2) * For three-wire, two phase circuits the current in the common conductor is 1.41 times that in either of the other two conductors. Post navigation Ohms LawFull Load Formula