What is Bitcoin Halving?

Bitcoin’s protocol specifies that new coins are created and distributed to miners as a block reward. This reward started at 50 BTC per block when Bitcoin launched in 2009 and is cut in half every 210,000 blocks — approximately every four years given average block times of around ten minutes.

Halvings that have already occurred:

• November 2012: Reward reduced from 50 BTC to 25 BTC
• July 2016: Reduced from 25 BTC to 12.5 BTC
• May 2020: Reduced from 12.5 BTC to 6.25 BTC
• April 2024: Reduced from 6.25 BTC to 3.125 BTC

The halving mechanism is central to Bitcoin’s fixed supply model. By reducing issuance on a predictable schedule, the protocol ensures that the total supply of bitcoin will never exceed 21 million coins, with the last bitcoin estimated to be mined around the year 2140.

After all bitcoins are mined, miners will rely entirely on transaction fees to sustain the network — a long-term economic question the community continues to discuss.

Halvings reduce the income of miners while their operational costs remain constant, which can lead to less efficient mining operations shutting down. Over time, as the block subsidy diminishes, transaction fees are expected to become a larger portion of miner revenue.

Halvings are predictable events; their schedules are publicly known well in advance and are verifiable on the blockchain by counting blocks.