How is vbyte calculated??
If your transaction is segwit, it would include some witness data. To calcualte the virtual size of a transaction, those witness data must be counted as one quarter the size of regular data.
Vbyte is virtual byte, also called as virtual size. From bytes to weight units, multiply it with 4.
For getting the weight units, you should multiply
virtual size of the transaction by 4, not the size.