The triode calculator can calculate the base resistance of the transistor when it goes into saturation or when driving an electronic switch.
By the load current saturation, the base current must be Ib = Ic / Beta. Transistors have different gains, so we'll use the lowest value of the beta to ensure saturation.
Rb= (VP-VBE)/Ib= (VP-VBE)*Magnification factor/Ic= (VP-VBE)*Magnification factor*Rc/VP
