How do I calculate the kp, ki and kd?

// PID variables

float PID_error = 0;

float previous_error = 0;

float elapsedTime, Time, timePrev;

int PID_value = 0;

// PID constants

**int kp = 203; int ki = 7.2; int kd = 1.04;**

int PID_p = 0; int PID_i = 0; int PID_d = 0;