Power Calculators


  • Amperes when kVA is known
  • Converting kVA to kW
  • Converting kW to kVA
  • Converting kW to HP
  • kVA Required to run motors
  • Guide to units:
    HP = Horsepower
    kW = Kilo Watts
    kVA = Kilo Volt Amps

    I = Ampere or Current
    V = Volts
    PF = Power Factor

    Calculating Ampere (I), given kVA.
    1, 2, 3
    = Ampere

    Converting kVA to kW
    kVA = kW
    Converting kW to kVA
    kW = kVA

    Converting kW to HP
    kW = HP

    What size genset is needed to start a 3 phase electric motor Direct on Line (DOL) start
    HP of
    = Generator
    kVA Required

    Generator Size to Start Motors

    Instructions: You only need to fill in the columns colored in orange.
    Fill in the HP of the motor's) in their starting sequence, select the start method (Direct On Line or Star Delta) and press Evaluate. The required generator size will then be displayed at the bottom.

    3 Phase (480 volt @ 60Hz)
    1 Phase (240 volt @ 60Hz)

    Starting Sequence Motor HP Start Method
    DOL / StarDelta
    Run Variable Phase Current Starting Value Total Run Current Total Start Current
    1 /
    2 /
    3 /
    4 /
    5 /
    6 /
    Generator Size for Starting with: kVA*
    Generator Size for Running with: kVA*
    Generator Size Recommended: kVA*


    NOTE: the above calculations are an estimate only because other factors such as site conditions, motor efficiencies and iron losses are not taken into consideration.


    Select Transformer Phase...
    Three Phase

    Single Phase

    Enter Two Known Values Below and Click "Calculate"