A Bitcoin halving is a programmed event that cuts the block reward miners receive in half every 210,000 blocks (roughly every four years). It enforces Bitcoin's disinflationary supply schedule, reducing the rate of new coin creation until the 21 million cap is reached.
What Is a Bitcoin Halving?
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The short version
Picture a gold mine that cuts its output in half every four years, no matter how many miners show up. That's the halving, it's a supply squeeze baked into Bitcoin's code from day one, making Bitcoin progressively scarcer over time.
How It Works
Every 210,000 blocks, the Bitcoin protocol automatically reduces the coinbase reward by 50%. The original reward was 50 BTC per block (2009). First halving at block 210,000 (November 28, 2012): 25 BTC. Second at block 420,000 (July 9, 2016): 12.5 BTC. Third at block 630,000 (May 11, 2020): 6.25 BTC. Fourth at block 840,000 (April 19, 2024): 3.125 BTC. This schedule is enforced by consensus rules, every node independently verifies that new blocks contain the correct reward amount. No entity can change it without convincing the entire network to adopt different rules. The halvings continue until the reward rounds down to zero (around 2140), at which point all 21 million Bitcoin will have been issued.
The April 2024 halving impact
Before block 840,000 (April 19, 2024), miners earned 6.25 BTC per block. At 144 blocks/day, that was 900 new BTC daily ($54M at $60K). At block 840,000, the reward dropped to 3.125 BTC, only 450 new BTC daily ($27M). Miners with electricity costs above ~$0.07/kWh on older-generation ASICs became unprofitable overnight and had to shut down or upgrade. The network hash rate dipped briefly by ~5% before recovering as the difficulty adjusted downward.
What People Get Wrong
The halving automatically doubles the price
Halvings reduce new supply but price depends on demand. Historically prices have risen after halvings, but correlation doesn't guarantee future results and timing varies by months.
The halving is a single dramatic moment
The halving is one block where the reward changes. The market usually prices it in gradually over the preceding months since the date is predictable.
Miners will quit after the halving
Less efficient miners leave, difficulty adjusts downward, and remaining miners become more profitable. The network self-balances, it has survived four halvings.
Keep Reading
Sources & Further Reading
- Bitcoin Block Reward Halving Countdown
Live countdown to the next halving with block-by-block tracking
- Bitcoin Supply Schedule (GitHub)
The actual Bitcoin Core source code implementing the halving schedule
Questions People Also Ask
- When is the next Bitcoin halving?
- The next halving will occur at block 1,050,000, expected around March-April 2028. The exact date depends on average block time between now and then.
- How many halvings are there total?
- There will be 32 halvings total before the block reward reaches zero. As of 2024, four halvings have occurred (2012, 2016, 2020, 2024).
- Does the halving affect transaction fees?
- Not directly. Fees are set by supply/demand for block space. However, as block rewards shrink, fees become a larger portion of miner revenue, which may influence fee market dynamics long-term.