How UTXOs can affect transaction fees

[Darker45]

By the way, it's here on the forum that I learned several years ago that there's actually no such thing as input in the Bitcoin blockchain. There are only outputs.

What do you mean by "there's actually no such thing as input in the Bitcoin blockchain"?
Every non-coinbase bitcoin transaction has inputs, and even Satoshi has used the word "input" in Bitcoin whitepaper.

I'm just casually responding to _act_'s statements about "having 1 input and 3 outputs" or "having 1 input and 1 output" statements as if there's actually Bitcoin transferred or moving from wallet to another when in fact there were only unspent outputs which are unlocked in new transactions which results into new outputs. In other words, inputs are simply references to unspent outputs that are to be consumed and labeled spent and removed from the set of unspent outputs after the transaction is confirmed.

[MisFoxie]

By the way, it's here on the forum that I learned several years ago that there's actually no such thing as input in the Bitcoin blockchain. There are only outputs.

What do you mean by "there's actually no such thing as input in the Bitcoin blockchain"?
Every non-coinbase bitcoin transaction has inputs, and even Satoshi has used the word "input" in Bitcoin whitepaper.

I don't know which input everyone is talking about if i know correctly every unspent UTXO become input when it's send to another address. If two UTXO is being used it become two input once those UTXOs send using single transection it become 1 output.

Inputs: 0.4 BTC+0.6 BTC=1 BTC
Output to recipient : 0.8 BTC
Change back to you : 0.199 BTC

In OPs case it's two input and two output which mean transection fee would be even higher because more input and output equal more vbytes and more vbytes mean higher transection fee.

[Mia Chloe]

~snip

If I can remember vividly I think there was a post recently that still revolves around this particular discussion. Anyways the thing is your UTXO count contributes a lot to your fees that's why most wallets try to consolidate and at the same time efficiently use inputs else you'll be using too much space than necessary.

Sometimes the difference is not very big and obvious especially now that we have very subsidized fee rates but it's still good to make it economical.

[Cookdata]

Inputs: 0.4 BTC+0.6 BTC=1 BTC
Output to recipient : 0.8 BTC
Change back to you : 0.199 BTC

In OPs case it's two input and two output which mean transection fee would be even higher because more input and output equal more vbytes and more vbytes mean higher transection fee.

No, it will not. The transaction fee is not large even if it's a legacy transaction, two input and output is not that large

Let's analyze the transaction details. The input is 0.4 BTC and 0.6 BTC, the output is 0.8 BTC and 0.199, that means the remaining amount is fee which is 0.001 BTC, that is 100k sats.

I don't know the kind of address OP want to use but I will go with native segwit. If you use Jlopp transaction size calculator, you are going to have a total of 209vByte. Let's say you decide to use 2 sats/vbyte to get a faster confirmation, you will spend just 418 sats in this transaction. You will still have roughly 99,582 sats left.

If you use a legacy address, you would probably be spending 75% higher than segwit on fee because of the witness discount.

[notocactus]

In OPs case it's two input and two output which mean transection fee would be even higher because more input and output equal more vbytes and more vbytes mean higher transection fee.

No, it will not. The transaction fee is not large even if it's a legacy transaction, two input and output is not that large

MisFoxie only means that it will cause a higher (bigger) transaction. In the post, I seen nothing implies as "large transaction fee". At least with latest and current Bitcoin mempool conditions, transaction fees are not too large, not too expensive compares to two or three years ago.

• Minimize your transaction fee with Electrum wallet.
  
  • Guide to check fees: Taker, maker, deposit, withdrawal, transaction fees.
  • There are links to topics, articles about transactions fees over days of week, hours of day.
• It's a simple guide with some small tricks on how to prepare for your transactions in the future especially during times when Bitcoin mempools are overloaded. Watch Bitcoin mempools, choose good times (days like weekend, hours) for consolidating small inputs.