Bitcoin Fee Estimator
Calculate the optimal fee for your Bitcoin Transaction
Our estimator lets you estimate the required fee for a Bitcoin transaction to be mined within the next 2 - 40 blocks.
Time since last block:
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FAQ
How are Bitcoin fees calculated?
Bitcoin fees have two important components. 1. the size of the transaction (in bytes). 2. the fee per byte. The size of a Bitcoin transaction can be calculated by looking at the amount of inputs and outputs. The optimal fee per byte changes constantly, look this up using our tool.
Once you know both the inputs & outputs of your transaction as well as the fee per byte you are willing to pay you can calculate the size of your transaction in bytes using the formula below. To calculate the current Bitcoin fee you then multiple the size of your transaction in bytes by the fee per byte you wish to pay. The result is the Bitcoin fee in Satoshi's.
However, using our tool there is no need to calculate. Just select the amount of blocks within which you'd like to have your transaction confirmed. When applicable you can also easily change the input & output values.
How is the fee for Legacy Bitcoin Transactions estimated?
We query our Bitcoin node for the estimated price per byte for a block window of n-blocks, n being the value you fill in as the 'Confirmed within' value. We then calculate the size of the transaction in bytes, this calculation is based on the total amounts of in- and outputs of the transaction; where the calculation (Bitcoin fee estimation for legacy transactions) is:
bytes = inputs * 146 + outputs * 33 + 10
Using this calculation a Bitcoin transaction with 1 input and 1 output has a size of 189 bytes. An example of such a transaction on the Bitcoin Blockchain can be found here Some assumptions have been made in this calculation. Ie: usage of compressed public keys (from Bitcoin client v0.6) lowering the size of inputs from 180 to 146 bytes. The standard setting sets the input as 1 and the outputs as 2.
You can change the values for in- and outputs by clicking on the +/- buttons. . The bytes calculation is an approximation and can differ by a few bytes in an actual transaction.
What are the differences between Segwit and Legacy Bitcoin Transactions?
Segwit stands for Segregated Witness and was introduced in BIP-0141 (Bitcoin Improvement Proposal 141). The size of a Segwit transaction is lower than the size of a legacy Bitcoin transaction, as Segwit reduces the overall size of the transaction. The difference lies mainly in the size of inputs, as the outputs are roughly the same in size - 1-2 bytes smaller when using Segwit. Thus, having a smaller transaction size, using Segwit will reduce your Bitcoin transaction fee , especially when sending multi-signature transactions as these are heavy on the inputs. Your wallet might not support Segwit natively and require an update before you can use Segwit.
Use the toggle in the upper right corner to opt for Segwit as a transaction type.
How is the fee for Segwit transactions estimated?
With BIP-0141 a new metric for measuring the size of a transaction, called Transaction Weight , was introduced. Which value is calculated by multiplying the size (in bytes) of parts of the transaction by different values. As a result there is a better balance between the cost of creating and the cost of spending an output compared to Legacy Bitcoin transactions - more information about Transaction Weights in Bitcoin .
In our calculation for the Segwit Transaction Weight - or vBytes - we assume inputs and outputs use P2WPKH resulting in:
vBytes = inputs * 68.5 + outputs * 31 + 10
What is the Fee Comparison?
The Bitcoin fee history/comparison widget shows information about Bitcoin fees over a certain time period and allows you to compare the current fee - shown in the top right of the widget - to the average, maximum and minimum fee in the selected period. Currently limited to data for confirmation within 6 blocks .
What are the inputs?
Within the Bitcoin ledger the input of a transaction is the wallet address from which the coins were sent. A transaction can have several inputs. An example of this would be a Bitcoin wallet that consists of three addresses, each containing 1 BTC. If the owner of that wallet wishes to send more than 1 BTC in a single transaction he must utilize more than one of his addresses, resulting in a transaction with more than one input.
What are the outputs?
The transaction outputs are the destination(s) of the input. Ie: the address(es) where the Bitcoin was sent to. It is common to have at least two outputs in a transaction. This happens when you have 1 BTC and only wish to send 0.5 BTC to someone else. The remaining 0.5 BTC change will be sent to a third address within your wallet.
What is the Unconfirmed Transaction Count & Mempool Size?
The unconfirmed transaction count is a value retrieved from our Bitcoin node and shows the amount of unconfirmed transactions our node has found. There is no single source of truth for the total amount of unconfirmed transactions on the Bitcoin blockchain.
The mempool size shown is a sum of the sizes of all unconfirmed transactions our Bitcoin node has found. This number is relevant because the size of a Bitcoin block is limited to 1 MB. The size of the mempool therefore says something about the chances of your transaction being included in the next block.
How often is the data updated?
The Satoshi/byte rate is refreshed every minute. Information about the Bitcoin Mempool and Unconfirmed Transactions is updated every 3 seconds. The Bitcoin price in USD is refreshed every second. Current Bitcoin Price: $loading...