Halving: How the Bitcoin Block Subsidy Is Cut in Half

Halving, also called the Bitcoin halving, is a rule built into the Bitcoin protocol that cuts the block subsidy, the newly created BTC paid to the miner of each block, by 50% every 210,000 blocks, about every four years at the 10-minute block target. The subsidy has been 3.125 BTC per block since April 2024.

How Does the Bitcoin Halving Work?

The Bitcoin halving is a rule in the Bitcoin protocol, which every node on the network enforces. A node is a computer that checks each new block against the protocol’s rules. The block subsidy started at 50 BTC per block and falls by half every 210,000 blocks, which is why the rule is also called the block subsidy halving.

The block subsidy is the newly created BTC that the creator of a block may claim in the first transaction of that block, called the coinbase transaction. An informal, older nickname for the halving is “the halvening.”

The halving follows the block count, not the calendar. The protocol aims for one block every 10 minutes, so 210,000 blocks take 2.1 million minutes, or about 1,458 days. That is about four years. The gap is only approximate because real block times vary.

No person or company triggers the Bitcoin halving. Every node rejects a block that breaks the issuance rule, meaning a block that claims more than the subsidy plus the transaction fees it contains. A miner therefore can’t skip a halving by claiming more. Moving the interval would take a change to the consensus rules, the shared rules that decide which blocks every node accepts.

The 2024 halving shows the rule in real blocks. Block 839,999 paid a subsidy of 6.25 BTC, and the next block, 840,000, paid 3.125 BTC. At the 10-minute target the network finds 6 blocks an hour, which is 144 blocks a day.

Before that halving, 144 blocks at 6.25 BTC each meant about 900 BTC of new issuance a day. After it, 144 blocks at 3.125 BTC each meant about 450 BTC a day.

Why Does Bitcoin Cut the Block Subsidy in Half?

The halving is the mechanism that sets how fast new BTC enters circulation. Bitcoin has no central issuer, so the protocol defines the issuance schedule in advance. Community protocol documentation describes the schedule as one that approximates how fast commodities such as gold are mined, and the 2008 Bitcoin whitepaper likens the steady addition of new coins to gold miners adding gold to circulation.

The halvings also produce Bitcoin’s supply cap. Each era of 210,000 blocks, the stretch between two halvings, creates half as much BTC as the era before it, so total supply keeps growing but ever more slowly and approaches 21 million BTC. “21 million” is the rounded name: the exact maximum is 20,999,999.9769 BTC.

Bitcoin Core, the reference software for the network, calculates the subsidy in whole satoshis. A satoshi is one hundred millionth of a BTC, or 0.00000001 BTC, the smallest recorded unit. Repeated halving therefore ends at zero instead of at ever-smaller fractions. The subsidy reaches zero at block 6,930,000, the 33rd halving, and the network is estimated to reach that block around the year 2140. That year is an estimate because it depends on block times.

After the subsidy ends, the Bitcoin halving schedule has no further steps and the block reward consists of transaction fees only. The whitepaper describes this design: once a set number of coins is in circulation, the incentive for nodes can come entirely from fees.

Which Halvings Have Happened, and When Is the Next One?

The Bitcoin halving has happened four times so far, after the first era that started with the genesis block. The table gives the halving history by block height, the date the network reached that height, and the subsidy that applied afterward. The two future rows are estimates.

Halving	Block height	Date reached (UTC)	Subsidy after (BTC per block)
Genesis block	0	January 3, 2009	50
First	210,000	November 28, 2012	25
Second	420,000	July 9, 2016	12.5
Third	630,000	May 11, 2020	6.25
Fourth	840,000	April 20, 2024	3.125
Fifth (next)	1,050,000	Estimated around 2028	1.5625
33rd (last)	6,930,000	Estimated around 2140	0

The fourth Bitcoin halving came at block 840,000 on April 20, 2024 (UTC), the evening of April 19 in US time zones. The block subsidy has been 3.125 BTC since then and stays at that level until block 1,050,000.

The next Bitcoin halving is at block 1,050,000, where the subsidy falls to 1.5625 BTC. As of October 2026 the network is about 76,500 blocks short of that height, which at the 10-minute target puts the halving around 2028.

What Does a Halving Change, and What Does It Leave Alone?

The Bitcoin halving cuts the block subsidy and nothing else. A block’s reward is the subsidy plus the transaction fees paid in that block, so the reward falls by less than half whenever fees are above zero. “Block reward halving” is therefore a common but imprecise name, because only the subsidy part of the reward halves.

Transaction fees stay outside the rule. The senders of transactions set the fees they pay, and the total varies from block to block. As of October 2026, fees made up about 0.56% of total block rewards over the latest 4,320 blocks, roughly four weeks, so the subsidy is nearly all of a block’s reward today. That share moves from day to day.

For Bitcoin mining revenue, the halving works as arithmetic and not as a forecast. Suppose the BTC price, the fees, the network difficulty, and the hashrate all stayed where they were. The halving would then cut the BTC a miner receives per block by close to half.

Network difficulty is the setting that controls how hard it is to find a valid block. Hashrate is the combined mining power of all miners on the network, counted in hashes per second. The price, the fees, the difficulty, and the hashrate move independently of one another, so the halving rule doesn’t tell anyone what miner revenue will be.

The halving does not reset network difficulty. The protocol recalculates network difficulty every 2,016 blocks, which is two weeks at the target pace, using block timestamps, whether or not a halving falls in between. The 2024 halving came in the middle of a difficulty period, the 2,016-block window between two recalculations, because 840,000 is not a multiple of 2,016.

The BTC price is not set by the halving either. The protocol rule says nothing about price: it is a supply rule, and nothing in it sets or predicts a BTC price or a miner’s revenue.

Can Anyone Name the Exact Date of the Next Halving?

No one can name the exact day of the next Bitcoin halving in advance. The protocol fixes the block height, 1,050,000, and not the date. The date is the moment the network finds that block.

Block times average 10 minutes only over time. When hashrate rises, blocks arrive faster until the next difficulty adjustment, and when it falls they arrive slower. As of October 2026, the running difficulty period is averaging about 9.4 minutes a block, and a date calculated at that pace lands about a month earlier than one calculated at exactly 10 minutes.

Long-range forecasts can miss by a wider margin. As of October 2026, a reference table of block heights labels its year column a forecast that may be slightly off, and its entry for block 840,000 says 2025, although the network reached that block in April 2024.

Countdown pages and calendars calculate a date from the blocks left and an assumed block time, so every such date is an estimate. The reliable reference is the block height: when the network reaches block 1,050,000, the halving has happened, whatever date a calendar showed.

The date of any halving not yet reached stays an estimate until the network finds the block.