CPFP Calculator for Bitcoin Transactions

Bitcoin's Child Pays For Parent (CPFP) is a fee-bumping technique designed for pending (unconfirmed) transactions, commonly referred to as "The Parent." In this method, a second transaction, known as "The Child," utilizes the outputs of the Parent(s) and covers all associated transaction fees. This approach ensures that both the Parent(s) and the Child are confirmed together and expedited.

This calculator will assist you in determining the exact feerate required for the descendant transaction (The Child). To use this tool, you must first select the desired feerate, which will become the effective feerate for both transactions. Additionally, include the parent transaction and the output over which you have control and intend to spend.

If the parent transaction has unconfirmed ancestors, they are also taken into account. However, it is crucial to note that the calculator assumes, based on this premise, that the descendant transaction (The Child) will have only one input and one output. Therefore, it's important to ensure that no additional inputs and outputs are included when making the transaction.

There is no need for your wallet to support Replace-By-Fee (RBF) to use this tool. However, if it does support RBF, enable the option for the new transaction (the child). After you broadcast the transaction, you can track its status and the resulting effective fee rate through our transaction analyzer.

The most common use case is when you are receiving a payment from somebody, for example, from an exchange, and the fee is not enough, but you want the transaction to be confirmed as fast as possible. In this scenario, you can use the CPFP calculator to spend the output that points to your address and confirm the transaction in the next Bitcoin block.

If you're unsure about handling this tool or if your wallet can't process spending on unconfirmed transactions, it'll be much easier to utilize our Bitcoin transaction accelerator service.