How do you know how much transaction fee to deduct before sending the payment?

[icedicedavid]

I have my fees set to 0.0001 BTC for my customers in the bitcoin.conf file for withdrawing funds from Ice-dice.com. However, occasionally transaction fee would end up being 0.0003 when the amount is large like this one: https://blockchain.info/tx/f15964762b001eee7350a4614c6357430bd0779a1b1af94784abcf0e73db2249

When this happens the accounts are no longer balanced because the extra transaction fee of 0.0002 that was not accounted for when I sent the transaction.

so my question is how would you guys deal with this problem?

[pedrog]

Set your fee to 0.0005.

[theymos]

You should probably just eat the fee or increase your other fees to compensate for the fees. You should not charge users for the fees caused by their withdrawals because the actual fee depends on transactions that other users are making. If someone funds their account with 100 transactions adding up to 0.2 BTC, the large number of transactions will increase fees for everyone. That transaction you referenced is expensive due to this kind of wallet fragmentation, not because the transaction's value is large.

I have my fees set to 0.0001 BTC for my customers in the bitcoin.conf file

That's unnecessary. Bitcoin-Qt will never use a too-low fee. Even if you set your fee to 0, you will pay fees.

[icedicedavid]

You should probably just eat the fee or increase your other fees to compensate for the fees. You should not charge users for the fees caused by their withdrawals because the actual fee depends on transactions that other users are making. If someone funds their account with 100 transactions adding up to 0.2 BTC, the large number of transactions will increase fees for everyone. That transaction you referenced is expensive due to this kind of wallet fragmentation, not because the transaction's value is large.

I have my fees set to 0.0001 BTC for my customers in the bitcoin.conf file

That's unnecessary. Bitcoin-Qt will never use a too-low fee. Even if you set your fee to 0, you will pay fees.

Thanks, I've raised the transaction fee to 0.0005, but now I'm starting seeing this kind of 0.0015 transaction fees which I'm eating up most of it. it seems quite expensive.

https://blockchain.info/tx/8dc313847cb52e4ea11022341314180f5080f870d617c05a49ea5b6bc7772094

how do I lower these wallet fragmentation to reduce fees?

[Peter Todd]

Thanks, I've raised the transaction fee to 0.0005, but now I'm starting seeing this kind of 0.0015 transaction fees which I'm eating up most of it. it seems quite expensive.

https://blockchain.info/tx/8dc313847cb52e4ea11022341314180f5080f870d617c05a49ea5b6bc7772094

how do I lower these wallet fragmentation to reduce fees?

You can't.

To be exact, once a transaction output is created, spending it under any circumstance will take some amount of data, about ~130 bytes IIRC. Fees for transactions are paid per byte of data; it has nothing to do with how much the transaction is worth for the most part. (some miners will mine high-value transactions for free, but there is a lot of demand for those "freebies", and miners lose a small amount of money by doing this)

What you need to do is stop making so many transaction outputs. You should be charging the fees for each withdraw or deposit separately, or just give your customers minimum withdraw and deposit amounts.

You can also use an off-chain transaction service like inputs.io to skip blockchain fees entirely.

[RoadTrain]

You should probably just eat the fee or increase your other fees to compensate for the fees. You should not charge users for the fees caused by their withdrawals because the actual fee depends on transactions that other users are making. If someone funds their account with 100 transactions adding up to 0.2 BTC, the large number of transactions will increase fees for everyone. That transaction you referenced is expensive due to this kind of wallet fragmentation, not because the transaction's value is large.

I have my fees set to 0.0001 BTC for my customers in the bitcoin.conf file

That's unnecessary. Bitcoin-Qt will never use a too-low fee. Even if you set your fee to 0, you will pay fees.

Thanks, I've raised the transaction fee to 0.0005, but now I'm starting seeing this kind of 0.0015 transaction fees which I'm eating up most of it. it seems quite expensive.

https://blockchain.info/tx/8dc313847cb52e4ea11022341314180f5080f870d617c05a49ea5b6bc7772094

how do I lower these wallet fragmentation to reduce fees?

The minimum fee most miners accept is 0.0001 per Kb. You aren't required to pay more unless you need faster confirmations.

[gmaxwell]

The minimum fee most miners accept is 0.0001 per Kb. You aren't required to pay more unless you need faster confirmations.

Practically every block has free transactions, the blockchain disagrees with you.

[icedicedavid]

You should probably just eat the fee or increase your other fees to compensate for the fees. You should not charge users for the fees caused by their withdrawals because the actual fee depends on transactions that other users are making. If someone funds their account with 100 transactions adding up to 0.2 BTC, the large number of transactions will increase fees for everyone. That transaction you referenced is expensive due to this kind of wallet fragmentation, not because the transaction's value is large.

I have my fees set to 0.0001 BTC for my customers in the bitcoin.conf file

That's unnecessary. Bitcoin-Qt will never use a too-low fee. Even if you set your fee to 0, you will pay fees.

Thanks, I've raised the transaction fee to 0.0005, but now I'm starting seeing this kind of 0.0015 transaction fees which I'm eating up most of it. it seems quite expensive.

https://blockchain.info/tx/8dc313847cb52e4ea11022341314180f5080f870d617c05a49ea5b6bc7772094

how do I lower these wallet fragmentation to reduce fees?

The minimum fee most miners accept is 0.0001 per Kb. You aren't required to pay more unless you need faster confirmations.

I have my bitcoind set at 0.0005BTC but it would still charge me 0.0015 for some transactions with higher fragmentations though.

[DeathAndTaxes]

You should probably just eat the fee or increase your other fees to compensate for the fees. You should not charge users for the fees caused by their withdrawals because the actual fee depends on transactions that other users are making. If someone funds their account with 100 transactions adding up to 0.2 BTC, the large number of transactions will increase fees for everyone. That transaction you referenced is expensive due to this kind of wallet fragmentation, not because the transaction's value is large.

I have my fees set to 0.0001 BTC for my customers in the bitcoin.conf file

That's unnecessary. Bitcoin-Qt will never use a too-low fee. Even if you set your fee to 0, you will pay fees.

Thanks, I've raised the transaction fee to 0.0005, but now I'm starting seeing this kind of 0.0015 transaction fees which I'm eating up most of it. it seems quite expensive.

https://blockchain.info/tx/8dc313847cb52e4ea11022341314180f5080f870d617c05a49ea5b6bc7772094

how do I lower these wallet fragmentation to reduce fees?

The minimum fee most miners accept is 0.0001 per Kb. You aren't required to pay more unless you need faster confirmations.

I have my bitcoind set at 0.0005BTC per KB but it would still charge me 0.0015 on a 3KB transactions with higher fragmentations though.

FYPFY

Fees are per KB.  Not sure why you thought raising the fee would lower the fees you pay.

[icedicedavid]

You should probably just eat the fee or increase your other fees to compensate for the fees. You should not charge users for the fees caused by their withdrawals because the actual fee depends on transactions that other users are making. If someone funds their account with 100 transactions adding up to 0.2 BTC, the large number of transactions will increase fees for everyone. That transaction you referenced is expensive due to this kind of wallet fragmentation, not because the transaction's value is large.

I have my fees set to 0.0001 BTC for my customers in the bitcoin.conf file

That's unnecessary. Bitcoin-Qt will never use a too-low fee. Even if you set your fee to 0, you will pay fees.

Thanks, I've raised the transaction fee to 0.0005, but now I'm starting seeing this kind of 0.0015 transaction fees which I'm eating up most of it. it seems quite expensive.

https://blockchain.info/tx/8dc313847cb52e4ea11022341314180f5080f870d617c05a49ea5b6bc7772094

how do I lower these wallet fragmentation to reduce fees?

The minimum fee most miners accept is 0.0001 per Kb. You aren't required to pay more unless you need faster confirmations.

I have my bitcoind set at 0.0005BTC per KB but it would still charge me 0.0015 on a 3KB transactions with higher fragmentations though.

FYPFY

Fees are per KB.  Not sure why you thought raising the fee would lower the fees you pay.

Oh whats why, the bitcoind setting is price per KB! I had a misunderstanding that it's a flat rate. ok now it makes sense. Let me try to lower it back to 0.0001 in my bitcoind