What is the Halving?
Last reviewed 2026-07-27
The halving is Bitcoin's pre-programmed 50% reduction of the block subsidy — the new bitcoin paid to the miner of each block — which occurs every 210,000 blocks, roughly every four years. It is the mechanism that enforces Bitcoin's fixed 21 million supply cap and steadily falling issuance rate.
How it works
When Bitcoin launched in January 2009, each mined block created 50 new BTC. The protocol cuts that subsidy in half at every 210,000-block interval, and the rule is enforced by every node, so no miner can pay themselves more. Four halvings have occurred so far: on November 28, 2012 (block 210,000) the reward fell from 50 to 25 BTC; on July 9, 2016 (block 420,000) from 25 to 12.5 BTC; on May 11, 2020 (block 630,000) from 12.5 to 6.25 BTC; and in April 2024 (block 840,000) from 6.25 to 3.125 BTC.
The fifth halving will occur at block 1,050,000 — currently projected for around April 2028, though there is no fixed calendar date because the timing depends on how fast blocks are mined — cutting the subsidy from 3.125 to 1.5625 BTC. Halvings continue until the subsidy rounds down to zero around the year 2140, at which point miners will be paid entirely by transaction fees.
For miners, each halving instantly cuts subsidy revenue in half, squeezing out operations with high electricity costs and historically driving consolidation toward the most efficient hardware and cheapest power.
Why it matters
The halving is the heart of Bitcoin's monetary policy: predictable, disinflationary issuance that no central party can change. Because each halving cuts the flow of new supply in half at a known block height, halvings anchor the widely debated four-year market-cycle thesis, and they are the reason bitcoin's annual issuance rate now sits under 1% — below the 2% inflation target most major central banks aim for.
Real-world examples
The April 2024 halving (block 840,000) reduced daily new issuance from roughly 900 to roughly 450 BTC. Litecoin and several other proof-of-work chains that forked Bitcoin's code inherit the same 50%-cut schedule at their own block intervals.
Related terms
Go deeper
Read our full guide to the 2024 halving and the road to 2028, or browse the complete crypto glossary.
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