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.

1 Answer 1


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.

  • 3
    The maximum block size is 250,000 bytes (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
    Commented Jan 28, 2014 at 20:50
  • 1
    @GregHewgill how did you come up with 2^64-1?
    – user11221
    Commented Oct 29, 2014 at 22:27
  • 2
    @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. Commented Oct 29, 2014 at 22:30

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