What is Bitcoin's supply schedule?
One of Bitcoin's most important properties is that its total supply is fixed and its issuance schedule is predictable. No central bank, no government, and no individual can change it.
The hard cap: 21 million
Bitcoin's code specifies that no more than 21,000,000 BTC will ever exist. Approximately 19.7 million have been mined as of 2025. The remaining supply will be gradually issued over the next century, with the final Bitcoin expected to be mined around the year 2140.
This hard cap is enforced by the network's consensus rules. Any miner who tried to claim more than the allowed block reward would simply have their block rejected by every other node on the network.
The halving
Every 210,000 blocks, roughly every four years, the block reward paid to miners is cut in half. This event is called "the halving."
| Halving | Year | Block Reward |
|---|---|---|
| Genesis | 2009 | 50 BTC |
| 1st | 2012 | 25 BTC |
| 2nd | 2016 | 12.5 BTC |
| 3rd | 2020 | 6.25 BTC |
| 4th | 2024 | 3.125 BTC |
The most recent halving occurred in April 2024. The next is expected in 2028.
Why this matters
The halving means Bitcoin's new supply issuance slows over time while demand can grow in any direction. Bitcoin's monetary policy is written in code and verifiable by anyone. You don't have to trust a central bank's intentions or a government's fiscal discipline, the supply schedule is public, immutable, and already decided.
Contrast with fiat money
The US M2 money supply grew from roughly $15 trillion in 2020 to over $21 trillion by 2022, a 40% increase in two years. Bitcoin's supply grew by approximately 1.8% over the same period. For those who believe monetary inflation gradually erodes the value of savings, this distinction is significant.
Past price performance is not a guarantee of future results. Bitcoin's price is highly volatile. The supply schedule is a fact; what the market does with that fact is not predictable.