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Topic: Transaction fee - size rounding (Read 739 times)

hero member
Activity: 518
Merit: 502
November 19, 2013, 03:31:58 AM
#6
Hopefully that avoids any future confusion.

Very clear, yes. Good example, thanks.
donator
Activity: 1218
Merit: 1079
Gerald Davis
November 18, 2013, 09:58:06 PM
#5
Updated wiki:

Quote
Sending
  • A transaction may be safely sent without fees if these conditions are met:
  • It is smaller than 10,000 bytes.
  • All outputs are 0.01 BTC or larger.
  • Its priority is large enough (see the Technical Info section below)

Otherwise, the reference implementation will round up the transaction size to the next thousand bytes and add a fee of 0.1 mBTC (0.0001 BTC) per thousand bytes[1]. As an example, a fee of 0.1 mBTC (0.0001 BTC) would be added to a 746 byte transaction, and a fee of 0.2 mBTC (0.0002 BTC) would be added to a 1001 byte transaction. Users may increase the default 0.0001 BTC/kB fee setting, but cannot control transaction fees for each transaction. Bitcoin-Qt does prompt the user to accept the fee before the transaction is sent (they may cancel the transaction if they are not willing to pay the fee).  Note that a typical transaction is 500 bytes, so the typical transaction fee for low-priority transactions is 0.1 mBTC (0.0001 BTC), regardless of the number of bitcoins sent.

Hopefully that avoids any future confusion.
legendary
Activity: 1022
Merit: 1001
I'd fight Gandhi.
November 18, 2013, 06:24:33 PM
#4
Thanks for the clarification! I was wondering about this myself.
hero member
Activity: 518
Merit: 502
November 18, 2013, 06:12:00 PM
#3
Ok, great! Thanks for the super fast clarification!
donator
Activity: 1218
Merit: 1079
Gerald Davis
November 18, 2013, 06:11:17 PM
#2
It is round up.  I will update the wiki this evening unless someone does it before me.

1 to 1000 bytes = 1KB for fee purposes.
1001 to 2000 bytes = 2KB for fee purposes.

Before someone correct it yes I know KB is usually 1024 bytes but the source code uses base 10 not base 2.  Note sure why but it doesn't and it isn't going to change now.
hero member
Activity: 518
Merit: 502
November 18, 2013, 06:09:47 PM
#1
Hello,

the wiki [1] states regarding the transaction fees that:

Quote
Otherwise, the reference implementation will round up the transaction size to the nearest thousand bytes and then add a fee of 0.0001 BTC per thousand bytes.

Now, "to round up" and "to the nearest" are contradictory.  Huh Which one is it? [2] doesn't help either.

[1] https://en.bitcoin.it/wiki/Transaction_fees
[2] https://bitcointalksearch.org/topic/bitcoin-qt-bitcoind-082-final-available-219504
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