user88845: Is it possible to calculate the transaction size from the transaction id ?

user46677: 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.)

88845: <p>Is it possible to calculate the transaction size from the transaction id ?</p>
 46677: <p><strong>No.</strong> That's not possible.</p>

<p>A transaction id is calculated from the raw transaction. More specifically the raw transaction is hashed twice with sha256: <code>sha256(sha256(rawtransaction))</code>.</p>

<p>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.</p>

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