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What is the Bitcoin halving?
The halving is the scheduled cut in half of the new bitcoin paid to miners for each block. It happens every 210,000 blocks, roughly every four years, starting from 50 BTC per block, until issuance stops near the 21 million cap.
What it means for you
A halving changes how many new bitcoin are created, not how many you hold; your balance and keys are untouched. The schedule is written into the protocol, so the date of the next halving can be checked in advance by block height.
How it works
The block subsidy started at 50 BTC and is cut in half every 210,000 blocks, about every four years at the 10-minute average. It is computed from block height alone: 25 BTC after the first 210,000 blocks, 12.5 after the next, and so on. Amounts are counted in whole satoshis, so after enough halvings the subsidy reaches zero, total issuance stops near 21 million, and miners are paid only transaction fees. BIP 42 fixed a code flaw that would have restarted the subsidy after 64 halvings.
An example
Say a miner finds a block in an era when the subsidy is 3.125 BTC, and the block's transactions pay 0.2 BTC in fees. The coinbase transaction can claim up to 3.325 BTC. A block found after the next halving carries a subsidy of 1.5625 BTC, while the fee part depends only on what senders paid.
Sources: BIP 42: A finite monetary supply for Bitcoin, bitcoin.org: Frequently Asked Questions, Bitcoin whitepaper (PDF), Satoshi Nakamoto, Bitcoin developer guide: Transactions · checked 4 October 2026
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