# <center><i class="fa fa-edit"></i> 4.6 Transaction Fees </center>
###### tags: `Blockchain`
The following notes are taken from [Coursera](https://www.coursera.org/learn/cryptocurrency/home/week/2)

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Definition:

transaction fee = value of inputs - value of outputs

- Fee goes to miner who records the transaction
- Cost resources for
- Peers to relay your transaction
- Miner to record your transaction
- Transaction fee compensates for (some of) these costs
- Generally, higher fee means transaction will be forwarded and recorded faster

### Current Consensus Fees
- No fee if:
- tx less than 1000 bytes in size
- All outputs are 0.01 BTC or larger, and
- Priority is large enough
- `Priority = (sum of inputAge*inputValue) / (trans size)`
- Otherwise fee is 0.0001 BTC per 1000 bytes
- Approx transaction size: `148 Nᵢₙₚᵤₜₛ + 34 Nₒᵤₜₚᵤₜₛ + 10`
- 10 for other information

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- Most miners enforce the consensus fee structure
- If you don't pay the consensus fee, your transaction will take longer to be recorded
- Miners prioritize transaction based on fees and the priority formula