How to calculate the transaction size?

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Is it possible to calculate the transaction size from the transaction id ?

Pankaj Kumar

Posted 2019-01-15T06:33:25.550

Reputation: 145

I think this should answer to your question more than exhaustively. If yes this can be marked as duplicate, I suppose.

AG23 2019-01-15T11:05:30.417

Answers

1

No. That's not possible.

A transaction id is calculated from the raw transaction. More specifically the raw transaction is hashed twice with sha256: sha256(sha256(rawtransaction)).

That means, that the id is always 256 bits long (64 characters). Because sha256 and hashing in general is a one-way-operation, it's not possible to calculate the size of the rawtransaction just from the transaction id.

if you need more information about a transaction, you have to fetch that from a client. In bitcoin core you can use gettransaction or getrawtransaction. (getrawtransaction only works if the transaction belongs to one of your addresses or you have txindex enabled in your wallet.)

Jack O'neill

Posted 2019-01-15T06:33:25.550

Reputation: 236

TXID is dsha256 +endian swap of the over-the-wire transaction serialisation.James C. 2019-01-15T10:28:38.750

That is part of the p2p protocol, not implementation, as this is how txids / prevouts are referenced in overthewire tx serialisations.James C. 2019-01-15T10:40:04.757