What is the Bitcoin halving, and why does it happen every 210,000 blocks?
Every 210,000 blocks, the number of new bitcoin paid to miners is cut in half. The rule is a few lines of code, and it is the reason Bitcoin's supply schedule is known decades in advance.
Education only, not investment, tax or legal advice. Crypto-assets are high-risk — risk disclosure.
The short answer
The Bitcoin halving is the automatic cut in the new-coin reward paid with each block. Bitcoin's software halves that subsidy every 210,000 blocks, roughly every four years. It has happened four times, most recently at block 840,000 in April 2024, taking the subsidy to 3.125 BTC.
Key takeaways
- Each block pays its miner a subsidy of newly created bitcoin plus the fees of the transactions it includes; the halving cuts only the subsidy.
- Bitcoin Core halves the subsidy every 210,000 blocks, starting from 50 BTC, so the schedule is fixed by block count, not by calendar date.
- Past halvings happened at blocks 210,000, 420,000, 630,000 and 840,000; the subsidy is now 3.125 BTC per block.
- The next halving is due at block 1,050,000. Its date can only be estimated from the pace of blocks, and a halving is not a price forecast.
What is the Bitcoin halving?
Bitcoin has no central bank. New coins enter circulation through mining: the first transaction in every block creates fresh bitcoin for whoever produced that block. The Bitcoin whitepaper describes this as both an incentive for the computers that secure the network and the way coins are first distributed4. Miners also collect the fees attached to the transactions they include4.
The newly created part is called the block subsidy. The halving is the moment the subsidy is cut in half. In Bitcoin Core, the reference software, the subsidy starts at 50 BTC and is halved once for every 210,000 blocks that have been mined12. Fees are not halved; only the new-coin part shrinks.
Block subsidy in each era, calculated from the rule in Bitcoin Core Source: [1]
| Era | Block heights | Subsidy per block |
|---|---|---|
| 1 | 0 – 209,999 | 50 BTC |
| 2 | 210,000 – 419,999 | 25 BTC |
| 3 | 420,000 – 629,999 | 12.5 BTC |
| 4 | 630,000 – 839,999 | 6.25 BTC |
| 5 (current) | 840,000 – 1,049,999 | 3.125 BTC |
| 6 | 1,050,000 – 1,259,999 | 1.5625 BTC |
Why does the halving happen every 210,000 blocks?
Because that number is written into the software. Bitcoin Core's main-network settings set the halving interval to 210,000 blocks2, and the subsidy function simply divides the current block height by that interval to count how many halvings have occurred, then halves 50 BTC that many times1. A comment beside the code notes that this works out to approximately every four years1. Nodes enforce the rule: Bitcoin Core's own test suite checks that a block whose miner "creates too much coinbase reward" is rejected, with the error code bad-cb-amount9.
The four-year figure comes from timing. The software targets one block every 10 minutes and re-tunes mining difficulty over a two-week window2, which is 2,016 blocks at the target pace. At exactly 10 minutes per block, 210,000 blocks would take about 1,458 days, just under four years. Real blocks arrive a little faster or slower than target, so the calendar date of each halving drifts.
Figure · How the subsidy is worked out
- 01Take block heighte.g. 900,000
- 02Divide by 210,000whole number: 4 halvings
- 03Halve 50 BTC 4 times50 → 25 → 12.5 → 6.25 → 3.125
- 04Block subsidy3.125 BTC + fees
When did past Bitcoin halvings happen?
Each halving is a specific block, so its date is simply that block's timestamp, the time recorded in the block header by the miner who produced it. The dates below come from the block data for each halving height5, cross-checked against a second public block explorer6, and converted to Coordinated Universal Time (UTC).
Halving blocks and their timestamps Source: [5]
| Halving | Block height | Block timestamp (UTC) | Subsidy after |
|---|---|---|---|
| First | 210,000 | 28 Nov 2012, 15:24 | 25 BTC |
| Second | 420,000 | 9 Jul 2016, 16:46 | 12.5 BTC |
| Third | 630,000 | 11 May 2020, 19:23 | 6.25 BTC |
| Fourth | 840,000 | 20 Apr 2024, 00:09 | 3.125 BTC |
Dividing the time between halving blocks by 210,000 gives the real average pace. From those timestamps, blocks arrived about every 9.0 minutes between the first and second halvings, about 9.6 minutes between the second and third, and about 9.9 minutes between the third and fourth5. That is why halvings have landed a little under four years apart.
When is the next Bitcoin halving?
The next halving will happen at block 1,050,000, when the subsidy drops from 3.125 BTC to 1.5625 BTC12. The block number is certain. The date is not, because nobody can know exactly how fast future blocks will arrive.
Worked example
Estimating the date from the block count
On 2 October 2026 the chain tip was block 969,4475. That leaves 80,553 blocks to go. At the 10-minute target, that is about 559 days, which points to around April 2028.
This is an estimate, not a date. If blocks keep arriving slightly faster than 10 minutes, as they did in past eras, the halving comes earlier; if they slow, it comes later.
Every new block updates that arithmetic, so the estimate shifts a little each day. Treat any exact day and hour quoted far in advance as a moving guess.
What does the halving change, and what does it not change?
Figure · Changes at a halving
Changes
- New bitcoin per block is cut in half
- New supply per day falls by half
- Fees become a larger share of miner income
Does not change
- The 10-minute block target
- Transaction fees, set by users
- Coins that already exist
The most direct effect is on new supply. At the target pace of 144 blocks a day, a 3.125 BTC subsidy creates about 450 new bitcoin a day, half the roughly 900 a day under the previous 6.25 BTC subsidy (illustrative, at exactly 10 minutes per block). For miners, the subsidy part of their income halves overnight in bitcoin terms.
Over the long run, the whitepaper expects fees to take over: once a predetermined number of coins is in circulation, the miner reward can move entirely to transaction fees4. Under the code, the subsidy reaches zero satoshis after 33 halvings, at block 6,930,000, and the total ever created by the schedule comes to just under 21 million BTC1.
What a halving does not do is set a price. The CFTC notes that the value of virtual currencies comes entirely from market supply and demand8, and the halving is known years ahead. Our explainers on how crypto markets work and on volatility cover what actually moves prices, and the Bitcoin profile covers the asset as a whole.
What mistakes do people make about the halving?
Common beginner mistakes
Treating the halving as a price promise
The rule cuts new supply. It says nothing about demand, and past price moves around halvings do not guarantee future ones.
Quoting a fixed date for the next halving
Only the block height is fixed. Any calendar date is an estimate that moves with the pace of blocks.
Thinking existing coins are halved
Nothing happens to bitcoin people already hold. Only the subsidy in new blocks changes.
Assuming exactly 21 million coins will exist
The code's own comments say total supply is less than 21 million3. The 21 million figure in the software is a validity limit, not a count.
Risk warning
Halving hype is a common sales pitch
Be wary of anyone promising gains tied to a halving. The SEC warns that crypto asset investments can be exceptionally volatile and speculative7. Never invest money you cannot afford to lose, and read our risk disclosure.
Frequently asked questions
How many bitcoin halvings have there been?
Four, at blocks 210,000 (2012), 420,000 (2016), 630,000 (2020) and 840,000 (2024)5.
Will the halvings ever stop?
Is the 21 million cap exactly 21 million?
No. Summing the subsidy schedule gives about 20,999,999.9769 BTC, because halving whole satoshis rounds down. Bitcoin Core's comments add that actual supply is lower than 21 million for various reasons3.
Who decides when the halving happens?
It is not scheduled by any company or committee. The interval is a consensus setting in the software that nodes run2, so the halving happens automatically when the chain reaches the next multiple of 210,000 blocks.
Do transaction fees get halved too?
No. Fees are paid by users and go to the miner on top of the subsidy4. The halving affects only the newly created coins.
The bottom line
The halving is a supply rule, not an event anyone schedules: every 210,000 blocks, the new-coin subsidy is cut in half. It has happened four times, the subsidy now stands at 3.125 BTC, and the next cut comes at block 1,050,000, on a date that can only be estimated. It changes how fast new bitcoin appear, not what bitcoin is worth.
Sources
- src/validation.cpp: GetBlockSubsidy — Bitcoin Core (GitHub) Primary source
- src/kernel/chainparams.cpp: main network consensus parameters — Bitcoin Core (GitHub) Primary source
- src/consensus/amount.h: COIN and MAX_MONEY — Bitcoin Core (GitHub) Primary source
- Bitcoin: A Peer-to-Peer Electronic Cash System — Satoshi Nakamoto, 2008 Primary source
- Bitcoin block data for heights 210,000, 420,000, 630,000 and 840,000, and chain tip (read 2 October 2026) — mempool.space block explorer API, 2026 Primary source
- Bitcoin block data for heights 210,000, 630,000 and 840,000 (cross-check) — Blockstream Explorer API, 2026 Primary source
- Exercise Caution with Crypto Asset Securities: Investor Alert — Investor.gov, U.S. Securities and Exchange Commission, 2023 Primary source
- Customer Advisory: Understand the Risks of Virtual Currency Trading — U.S. Commodity Futures Trading Commission Primary source
- test/functional/feature_block.py (Bitcoin Core functional tests) — Bitcoin Core project (GitHub bitcoin/bitcoin), 2026 Primary source
How we checked this page: every figure above links to the numbered source it came from. Spotted an error? Tell the desk — see our editorial policy.
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