Incorrect bitcoin transfer amount from coinbase

[cryptosize28]

I am planning to transfer all of my bitcoin from Coinbase to Electrum and I did a test transaction with only .001 bitcoin. The transfer completed however my Electrum wallet shows 0.1 mBTC rather than 1 mBTC. I am very hesitant to transfer any more bitcoin if this issue persists. Please advice.

[BitcoinNewsMagazine]

Check the transaction on a block explorer, also double check your decimal point. See if an incorrect balance is due to a fee Coinbase charged you.

[kolloh]

Yeah, this is likely due to an incorrect transfer amount or fee deduction from Coinbase. Although I wouldn't think they would deduct the fee from the amount you specify as this wouldn't allow you to send an exact amount. I definitely recommend you look up the transaction on an explorer such as blockchain.info to verify the amounts sent and the fees on the transaction.

[cryptosize28]

Thanks everyone! This is my first time transferring bitcoin, an exciting moment :-)
The transaction fee was 0.002. How does the math add up if I only transferred .001?

[Quartx]

Thanks everyone! This is my first time transferring bitcoin, an exciting moment :-)
The transaction fee was 0.002. How does the math add up if I only transferred .001?

Check the transaction on coinbase and give us the tx id, chances are, coinbase told you the maximum you could transfer after deducting fees due to low balance and you did not read properly.

[cryptosize28]

f3b376ce3ff45aefded8a751847acd09b8e5ab4bc2060b42ceb7ddc994d70dcf

[HCP]

wow... coinbase smashed you with fees: https://blockchain.info/tx/f3b376ce3ff45aefded8a751847acd09b8e5ab4bc2060b42ceb7ddc994d70dcf

Total Input 0.00266313 BTC
Total Output 0.00013752 BTC
Fees 0.00252561 BTC
Fee per byte 487.569 sat/B

You just paid ~US$7 (0.00252561 btc) to send ~0.28c (0.0001)

What you need to realise with bitcoin, is that when you receive bitcoins, you don't necessarily end up with a one big lump sum of funds like you would with a normal bank account. All of the amounts received remain as separate chunks until you want to send coins somewhere. Each "chunk" you need to use as an input to a transaction will add ~148 bytes to the transaction size. Transaction fees are calculated in satoshis PER BYTE... so the more bytes, so more you pay in fees.

It seems like you have received a number of "dust sized" payments (from faucets or mining perhaps?):
0.00088771 BTC
0.0008877 BTC
0.00088772 BTC

Anyway, you've attempted to send 0.0001, which would theoretically be covered by a single 0.008877 BTC Unspent Transaction Output (UTXO), but Coinbase has wanted to send a large fee of 487.569 sats/Byte to prioritise your transaction and get it confirmed quickly.

A "standard" transaction of 1 input, and 2 outputs will be around 226 bytes in size... so coinbase has calculated that your fee required is 226 bytes * 487.569 sats/byte = 110190.594 sats = 0.001.  This means that your send Amount + Fee would be 0.0011.

However, the transaction only had one input of 0.0008877, which means that it has had to add another 0.0008877 input so you have enough inputs(2x 0.0008877 = 0.0017754 BTC) to cover the Send Amount + Fee (0.0011 BTC).

However, adding a second input adds another 148 bytes to the transaction... so now your transaction size would be 374 bytes... so the fee would now be 374 * 487.569 = 182350.806 sats = 0.00182350... which means that your two inputs isn't enough...

So it adds a 3rd input of 0.0008877... and ANOTHER 148 bytes (each input = ~148 bytes)... so now your transaction size is 518 bytes... fee is 518 * 487.569 = 252560.742 sats = 0.00252560...

Total you're wanting to send is 0.0001 + Fee of 0.00252560 = 0.00262560. All your inputs (3x 0.0008877) now total 0.0026631... so you can cover the entire lot (and have some spare)

TLDR; Morale of this story: DON'T collect dust amounts of BTC (that is pretty much anything less than 0.001)... and DON'T send dust amounts of bitcoin anywhere...

[cryptosize28]

@HCP - got it, thank you so much! I will not send any more dust amounts of BTC. This was really just a test to make sure that the Coinbase to Electrum transfer goes smoothly with no hiccups. I just wanted to send a very small amount as a test, as this is my first time doing so.

The one thing I'm still struggling with though is I sent 0.001 BTC, not 0.0001. Am I missing something?! Also, when I submitted the transfer on Coinbase, it said that my fee would be $3.25. Was this just an estimate? Meaning, when I send BTC in the future, I may end up paying significantly higher fees than what Coinbase notified me of?!

[BitcoinNewsMagazine]

Well, the blockchain says you sent .0001. You would have to post some screenshots from your Coinbase account if you believe otherwise.

[cryptosize28]

http://imgur.com/a/Iz9Ma

Let me know if that works - thanks!

[BitcoinNewsMagazine]

Let me know if that works - thanks!

$3.32 is only 0.00119767 btc at bitcoin price of $2772, and the fee for that transaction was 0.00252561 btc so you would have to ask Coinbase on this one. Could be a hiccup on their end.

[cryptosize28]

I'm thinking now that the .0011 difference (I transferred .001 BTC but only received .0001) is the fee. I'm just confused as to why coinbase is saying the fee was .0002

[HCP]

That is a very misleading UI. That figure of -0.00119767 BTC makes no sense to me... 

There is no combination of inputs/outputs in your transaction that make up that number? And that certainly isn't the amount that would have been take from your account.

The total of the inputs was: 0.00266313 BTC

The total output to your 39GwH address was: 0.00010000 BTC
and then some change to your coinbase acc: 0.00003752 BTC

Everything else got gobbled up as "Network Fees": 0.00252561 BTC

End result being that you would have got 0.0001 in your Electrum wallet, and your Coinbase wallet would have had 0.00262561 BTC total deducted from the balance (0.00266313 total inputs - 0.00003752 change returned) 

I would recommend that you keep that screenshot and send it to Coinbase support and ask them politely to "Please Explain"... because something is messed up there.

[cryptosize28]

Thank you everyone for your input! I've posted to the Coinbase community. Hopefully they will respond :-)

[aTriz]

Thank you everyone for your input! I've posted to the Coinbase community. Hopefully they will respond :-)

The deduction of 0.001 is bitcoin from your account likely included a block chain miners fee of at least 0.001 btc being deducted from your account, which means that the actual amount that you receive I'd whatever amount on your account history minus the transaction fees at the time. I'm pretty sure that's how coinbase operate, I haven't used them in a while so please point out if this is wrong.

@HCP - got it, thank you so much! I will not send any more dust amounts of BTC. This was really just a test to make sure that the Coinbase to Electrum transfer goes smoothly with no hiccups. I just wanted to send a very small amount as a test, as this is my first time doing so.

The one thing I'm still struggling with though is I sent 0.001 BTC, not 0.0001. Am I missing something?! Also, when I submitted the transfer on Coinbase, it said that my fee would be $3.25. Was this just an estimate? Meaning, when I send BTC in the future, I may end up paying significantly higher fees than what Coinbase notified me of?!

No. Coinbase tells you exactly how much you will be charged for. So the amount you send should match the amount you receive in your actual wallet. However the miners fees can fluctuate from time to time.