To calculate the power supply requirement you need to know how many watts are required by each motor and as you have not told us the motor coil resistance we cannot work that out.
Post a link to the datasheet for the stepper motors.
To calculate the power supply requirement you need to know how many watts are required by each motor and as you have not told us the motor coil resistance we cannot work that out.
Post a link to the datasheet for the stepper motors.