How to calculate size. found


in*180 + out*34 + 10 plus or minus 'in'
For example, this transaction has 40 inputs and 16 outputs. That gives us a transaction size of

40*180 + 16*34 + 10 +- 40
i.e. 7754 +- 40 bytes. The actual size is 7761 bytes.

Could you please clarify about  +- 40

BR!