Hello,

How does electrum (or any other wallet) compute the optimal network fee for a bitcoin transaction ?
Or how does this website https://bitcoinfees.earn.com/ compute the appropriate estimate fee ?


I know that you need to take in consideration the number of input/output, and you need to consider the number of unconfirmed transaction, however I want a technical way to compute it myself.



Please do not reply with an API link or any third party service, I would like to do it using opensource tools only.