Confirmation
A Bitcoin confirmation is a block mined on top of the block that holds a transaction, so a transaction in the newest block has one confirmation.
Each block on top of the one holding your transaction is one more confirmation. Six or more is final for most purposes: undoing it would take more computing power than anyone has.
How many confirmations are enough?
It depends on the amount. One confirmation already makes a reversal unlikely; six, about an hour, is the usual standard for large payments, because undoing them would need more computing power than the rest of the network for that whole hour.
How long does one confirmation take?
A new block arrives about every 10 minutes on average, but the gaps vary a lot: under a minute sometimes, over an hour rarely. Whether your transaction gets into the next one depends on the fee rate it pays.
Sources
- Bitcoin: A Peer-to-Peer Electronic Cash System (the white paper)
- Bitcoin developer guide: block chain
Updated 10 Oct 2026
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