Question: how kva rating of transformer is calculated?
Answer: Use the formula: P(KVA) = VA/1000 where P(KVA) is power in KVA, V is voltage and A is current in amperes. ... For example, if V is 120 volts and R is 50 ohms, P(KVA) = V^2/R/1000 = (14400/50)/1000 = 288/1000 = 0.288 KVA. Calculate power rating in KVA when you know power in watts and the power factor.