Transistor Switch Saturation Calculator

Rc (Collector resistor) (KΩ)
VP (Positive Voltage) (V)
Beta(min) (Current gain)
VBE (Base to emitter drop) (V)
Rb (Base resistor) (KΩ)

To saturate with the load current, the base current must be Ib=Ic/Beta. Transistors have different gains, so we have to use the lowest value of Beta to ensure saturation.

Rb= (VP-VBE)/Ib= (VP-VBE)*Beta/Ic= (VP-VBE)*Beta*Rc/VP