Bitcoin Forum

Is there any way to calculate the fee of the transaction I will make? I want to calculate because I don't currently have the coins I want to spend. If I had them the client would tell me hoe much is the fee.
Is there a site or a way to calculate it?

The fee you need to pay depends on how congested the network is,  are you trying to work out the minium fee you can send to get confirmations or are you trying to work out the fee you need to pay to get it confirmed as soon as possible? 

see here https://bitcoinfees.21.co/ , fee is satoshi per byte,just multiply it ,simply use your logic

That is not correct. Even if the network was 'a little' congested, the fee that needs to be included is based on the recommended fee at that time. This is because there could be a lot of TX's in the 30-40 satoshis/byte range, but at other times we could be looking at the same number of TX's but with >100satoshis/byte fees (at which time the recommended fee would be higher).

This website is a good source, yes.

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What wallet are you using OP?

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Update: Clarified a certain part.

I am using Official Bitcoin Wallet on Android phone.

lauda first says its not correct..

then rambles on to explain its linked to lots of tx's,

the reason it would get to 100sat/byte is because the previous block had lots of tx's and was 90.
the reason it would get to 90sat/byte is because the previous block had lots of tx's and was 80.
the reason it would get to 80sat/byte is because the previous block had lots of tx's and was 70.
the reason it would get to 70sat/byte is because the previous block had lots of tx's and was 60.
the reason it would get to 60sat/byte is because the previous block had lots of tx's and was 50.
the reason it would get to 50sat/byte is because the previous block had lots of tx's and was 40.

lets ask him this, if there lots LOTS OF TX's(congestion) causing people to outbid each other..  then isnt the price linked to congestion. and not some magical unicorn deciding "today everyone pays 100, because its my age"....

its not a game of darts where people throw a random number..

the price is not linked to randomness or magic.. its based on people outbidding eachother. where the price only needs to be outbid by alot if the congestion is high.
you have literally given the evidence that its true in your rebuttle. so unless the price is actually linked to unicorns or darts, please be honest with people.

I think your contradicting yourself here.  With all due respect your telling me im wrong but then explaining that if the network is congested then the fee will go up. Therefore the fee that you pay totally depends on the congestation of the network.  A fee that confirms today does not necessarily mean it will confirm tomorrow if the network has higher congestion and more people are using higher fees.

I didn't contradict myself, I may have improperly expressed myself. I've tried to clarify it with an update.
Let's assume that we have the same amount of congestion in two scenarios (separate events/days). In the first scenario, most fees were in the (e.g.) 10-20 satoshis/byte range. In the second scenario most fees were in the 100-110 satoshis/byte range. As such, scenario 1 would have had much lower recommended fees even though scenario 2 had the same amount of congestion. While your statement might not contextually be wrong, it can't stand alone as a completely correct statement. Let me try with a single sentence:

Two events of similar congestion (as 'same' is improbable in practice) can require different recommended fees.

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Does that make more sense now?

Doesn't it have custom fee settings? Are you okay with paying a bit more on default?

I didn't see any custom fee settings. I'll take a look though. I am okay with that but I was curious how can I calculate the fee so I don't send a smaller amount to cover the fees.

Well, the calculation isn't hard if you know the size of your transaction (which depends on a number of things, mostly inputs and outputs). Let's say that the transaction is going to be 400 bytes big. Now you open a website such as this one:
and multiply the TX size (in this case 400) with the recommended fee (currently 60 satoshis/byte). In this example the recommended fee (at the time of writing) would be 24 000 satoshis.

Be careful with https://bitcoinfees.21.co/ recommended fee.

At this time the recommended fee is 60 sat/byte, with a 0 block wait.
They advertise a 90% accuracy on that figure.

There are 3800 transactions at 60 sat/byte fee waiting in the mempool.
And hundreds of higher fee transactions.

I can say with 90% accuracy they are wrong.
If you pay 60 sat/byte at this time, you will not get into the next block.

If you use Mycelium android wallet, you won't have to calculate the fees. the wallet itself will make the recommended fees according to the transaction size. you can also choose between normal or economic fees 

Sad thread.

Absolutely not needed.

Thanx to BS limit supporters....

Block just found, 2250 transactions at 60 sat/byte now in the mempool.

At this time the recommended fee is 60 sat/byte, with a 0 block wait.
They advertise a 90% accuracy on that figure.

I can say with 90% accuracy they are wrong.
If you pay 60 sat/byte at this time, you will not get into the next block.

I don't think so everyone has much time while sending transactions that he keeps calculating the satoshis per 60/bytes. I suggest you to put at least 0.0002 per 1kb . I have never sent any transaction with fee lower then 0.0002 . So just set your wallet min fees @0.0002 . And if you are thinking how much the size will increase with the number of outputs try to put 0.0002 for 2 outputs and 0.0004 for 4 outputs and keep increasing the fees with the number of outputs . It's better to put higher fees then waiting hours for the transaction to confirm .

Ask SWIFT next time....

I doubt they are any more accurate than 21, I may be wrong.

I was showing that the correct recommended fee is not as correct as implied.
Although 90% accuracy is claimed by 21 on that correct fee/timescale, I was able to call it almost certainly wrong.

And I was correct.

Did you have a particular site in mind, I'll check for you.

If you send a transaction with such low fees you will be left waiting.

0.0002 per 1kb is one third of the present correct recommended fee, which I have shown to be incorrect, due to being too small.
You will be waiting hours. (the longer you wait the less accurate the 21 recommended fee becomes)

I don't think so well i mostly sends transactions with 0.0002/1kb , I gamble on luckyb.it and the transaction get confirmed very soon (whenever a block is found ) , However due to current situation 0.0004 is OK for 1kb right ? and 0.0002 under 500.

Your right, fee estimate is not perfect at 21, I guess they just use past data and not take into consideration number of unconfirmed transactions in mempool at particular fee, otherwise the recommended fee would go up if almost 4000 unconfirmed transactions used such recommended fee already.

But the fee estimate algorithm become better over time, I dont doubt about that. If I really need transaction to be confirmed in the next block, I pay much higher than recommended fee. If not, I pay lower obviously. What I dont see obvious is what is so special about 1 MB, its not even defined as 2^20 bytes - weird.

There is also luck in play but,

"The fastest and cheapest transaction fee is currently 60 satoshis/byte," - 21
1kb x 60 sat = 0.0006.

So no, 0.0004 is not technically ok. It is a lower than recommended fee, at this moment.

21 say, "The predictions are based on blockchain data of the last 3 hours, as well as the current pool of unconfirmed transactions (mempool).
First, a likely future mempool and miner behavior is predicted using Monte Carlo simulation. From the simulations, it can be seen how fast transactions with different fees are likely to be included in the upcoming blocks."

So they are trying.
But the only way to be more "accurate", as you say is to pay more.
The only way 21 can ultimately be more accurate is to recommend higher fees.

Interesting though, according to http://www.bitcoinqueue.com/details/ the last block (418410) contained far more 50 sat/byte fees than 60 sat/byte fees.
(i have issues with the accuracy of bitcoinqueue, but it did seem to tally roughly there with 21. there were 100's of 60 sat/byte fees waiting btw)

So paying the correct recommended fee maybe too low or too high!

(i am avoiding talking of blocksize here, although it leads to this fees problem. You may like my thread, https://bitcointalk.org/index.php?topic=1410211.0)