how calculate the energy use for starting a 3 phase motor until return to normal work?

hello everyone , for a project i must calculate the exact energy that used for start of motor until the motor return to normal work
in other words how much energy use for normal work of this motor equals the starting energy ?
the motor is 3 phase 20 Ampere 9KW
unfortunately i have no complete details but overestimately could you tell me will 10 second of normal work equals the starting energy ?