Bitcoin Forum

Hey guys, need help! I need get fee before send transaction!? How?!

I have Bitcoin Core 0.15 installed and using RPC.


 ??? ??? ??? ???

You can use a website like bitcoinfees.21.co (http://bitcoinfees.21.co) to see the appropriate fee per byte if that is what you are asking. I believe that there is an RPC command "estimatefee <numberofblocks>" that should return the required fee per kilobyte that will get your transaction confirmed in the specified number of blocks.

There is such a command and the fee estimations have drastically improved in 0.15.0. However if the user does not know something like this then they shouldn't be using RPC to create transactions. I didn't get a impresison that the user is very experienced based on their post. This is why I'd recommend OP to use the GUI. The interface is very simple:

https://i.imgur.com/mbNn0P2.png

Like Lauda says: Maybe a more user friendly wallet? Look at Exodus, if you are choosing a more user friendly wallet. I really like the design of Exodus :)

Bitcoin Core already has a "user friendly" fee estimator. Check the screenshot.

Meanwhile, Exodus fee customization is terrible - (maybe too much user friendly?); They overpay fees when lower transactions would be confirmed in the same time, and don't let you choose your fee because "users will use a low fee without thinking and risk their transaction not getting confirmed"; I wouldn't recommend them if you want to save money.

You should not sacrifice security and quality for convenience.

Unless they have updated their fee estimations to those used in Bitcoin Core 0.15.0 and later, they definitely are overestimating for every tier.

Yah, has estimate, but I am not want this. I need be more exact. Then

I have estimate 0.00037674 per kilobytes and yet I don't know what size of transaction to do (estimate-per-kilobytes/1024)*size-of-transacion. ( correct me if I'm wrong)

Size of transaction is depende the input and ouputs. If I have this informaction can I get the exact fee? Making this formula

Yes, you can be quite exact if you know the amount of inputs and outputs. It is quite easy to find transactions on a block explorer with the same numver of inputs and outputs and you will be able to see their size.

Thanks man!. Then stayed this way:

fee = (estimate-per-kilobytes/1000) * ((input * 180 + output * 34) + 10) edited

For the record... A "kilobyte" in Bitcoin is 1000 bytes, not 1024.

Also, "compressed" addresses, would only be around 148 bytes per input, so using 180 may result in overestimating the size in some cases.

Couldn't agree more. Exodus looks nice and all but as long as you can't export private keys I don't feel comfortable using it. That's why I started using electrum.
Electrum offers total access of public and private keys all combined into a fairly user-friendly UI design. Of course not as pretty as Exodus but I like being in control of things.
 

Thanks man!! thanks a lot!. anywhere I can't find description so simple