Next Block

What fee rate will get your transaction confirmed into the next block?


Last block height: 852907 (7 minutes ago)
6 sat/vByte
7 sat/vByte
10 sat/vByte
Samourai Wallet | Sentinel | OXT |

How does this work?

The Next Block estimator assesses all the unconfirmed transactions in the mempool, then computes at what miner fee rate a transaction needs to be broadcasted right now for it to be confirmed into the next block.

  • High = 99% probability your transaction will confirm in the next block
  • Medium = 50% probability your transaction will confirm in the next block
  • Low = 10% probability your transaction will confirm in the next block

If you want a detailed explanation, read the original Readme.

Who is this tool for?

Any individual who has two objectives when broadcasting a transaction:

  • Objective 1: have your transaction confirmed in a timely manner, ideally in the next block
  • Objective 2: reduce the amount of overpaid miner fees

Why is this fee estimator different to others available?

There are many methods which attempt to provide you with a miner fee rate estimation, some of these are integrated into bitcoin wallets, some are standalone applications. To date we have found most to be unreliable particularly during moments of miner fee rate volatility. Any application or tool which tells you "your transaction is expected to be confirmed within 4/6/12/24 blocks" is being dishonest as its calculation uses already confirmed blocks to draw this conclusion which is a flawed methodology.

By assessing the unconfirmed transactions within the mempool, this tool provides instead an instant snapshot probability for being confirmed in the next block. Attempting to calculate beyond this (i.e. for your transaction to be confirmed 6 blocks from now) introduces too many variables which would make any calculation mathematically unsound. These variables which can not be accurately accounted for include:

  • Block confirmation time variance
  • Unknown state of future mempool

Why is the fee rate the same for two or all three of the percentages?

This is normal and occurs very frequently because at that moment in time unconfirmed transactions in the mempool are weighted around a particular popular miner fee rate. As the weight of miner fee rates in the mempool diverge, in turn so will the calculation for the 10%, 50%, and 99% fee estimator value.

If I broadcast a transaction with the 99% miner fee rate it will confirm in the next block, right?

We would love to say yes, but unfortunately we cannot. 99% is a snapshot probability and the mempool state may drastically change between you broadcasting the transaction and the next block being mined. However in our experience with Objective 1 and 2 in mind, our next block fee estimator is far superior than others.