What the maximum number of txout in a transaction?


I know the maximum transaction size is 500Kb.

I also know there is a maximum for sigop in a transaction (20,000?).

What I'm interested in is what is the maximum number of txouts you could include in a single transaction.


Posted 2014-01-28T16:54:52.183

Reputation: 126



There is no practical maximum number of outputs in a transaction. The number of transactions can be up to 264-1, or 18446744073709551615. The transaction fee would be more than the total bitcoins to ever exist.

Greg Hewgill

Posted 2014-01-28T16:54:52.183

Reputation: 3 351


The maximum block size is 250,000 bytes (https://en.bitcoin.it/wiki/Transaction_fees). txin is approximately 148 bytes, a txout is about 34 bytes. Assuming 1 txin then max_txout ~= 7348. However, I believe that calculation is also limited by the max sigop limit.

– user789235 – 2014-01-28T20:50:49.480

@GregHewgill how did you come up with 2^64-1? – George Kimionis – 2014-10-29T22:27:13.113


@GeorgeKimionis: The number of transactions is stored in the Bitcoin block as a Variable length integer, which has a maximum range of 2^64-1.

– Greg Hewgill – 2014-10-29T22:30:28.543