def calculate_raw_tx_size(num_inputs, num_outputs):
tx_size = (num_inputs * BYTES_PER_INPUT) + (num_outputs *<EOL>BYTES_PER_OUTPUT) + FIXED_EXTRA_BYTES + num_inputs<EOL>return tx_size<EOL>
To calculate the transaction size:
    tx_size = (num_inputs * BYTES_PER_INPUT) + (num_outputs * BYTES_PER_OUTPUT) + FIXED_EXTRA_BYTES +/- num_inputs

We'll choose the upper bound, so:
    +/- num_inputs  =>  + num_inputs

Equation and constants are taken from http://bitcoin.stackexchange.com/a/3011.

:param num_inputs:
:param num_outputs:
:return: