How do I calculate the frequency of an FM transmitter circuit?
$$F = \frac{1}{2\pi\sqrt{LC}}$$

L and C2 are components oscillator

but this is a very awful bad circuit.

1 transistor as oscillator an as modulator is not the way to do it
it isn't as stable as an regular modular transmitter

for just a sine out you wont use this circuit 
you could look on the Internet for


Colpitts oscillator
Hartley oscillator
clapp oscillator
Meissner / armstrong oscillator
Wien bridge oscillator
...


or some VFO (Variable ferquency oscillator)


PLL
DDS
...


or when is must be very stable a XTAL oscillator 

For just data send and receive
google for 
433MHZ serial data 
433 psk data 
433 spi
...