As mention by Audioguru,
I think you are trying to use a transistor as a switch.
Transistor can be classified into 2 type of operation.
- transistor as a switch
- transistor as an amplifier
When you are using it as a switch,
parameter such as beta is of little or no use.
Often I will look into the current "Ic" it can handle as a switch.
It is the most important parameter when used as a switch.
Same as the property of a push button switch,
it determine the current capacity of the switch.
Ib, Vbe or gate voltage helps to compute the resistor Rb on the base.
Most of the time, I don't compute at all, and typical use 1kohm as Rb.
Unless the application requires power saving or design is complicated.
Perhaps you can provide us a schematic,
I am sure friends here are able to solve you problem precisely.
Friends here are very friendly.
Using transistor as a switch is actually very simple.
I have attached a article on this topic that I have for your reference.
**broken link removed**
I believe it should be what you are looking for.
And hopes the article can provide you a new perspective
of looking at a transistor.
Best Regards,
Siong Boon
www.siongboon.com