We're using bitcoind on our server.
When people withdraw from our system we want to have the correct miner fee.
I understand that we can get the good miner fee from txconfirmtarget or the API from: https://bitcoinfees.21.co/api
But when we send a transaction how do we know which miner fee to put if we want to enter it into the database?
EDIT: I do notice this: bitcoin-cli estimatefee 2 but then how do we find out how many bytes are being sent?