21 Million

How It Works

Bitcoin's supply cap is not a suggestion, a policy target, or a promise by a management team. It is a consensus rule embedded in the protocol, enforced independently by every full node on the network. Approximately every ten minutes, a new block is mined and new bitcoin is issued as a reward to the miner. This reward started at 50 bitcoin per block in 2009, was cut to 25 in 2012, to 12.5 in 2016, to 6.25 in 2020, and to 3.125 in 2024. Every 210,000 blocks — roughly four years — the reward halves again.

This halving schedule continues until the block reward becomes so small it rounds down to zero, which will happen around the year 2140. At that point, exactly 20,999,999.9769 bitcoin will have been mined. The sum is commonly rounded to 21 million. After that, miners will be compensated entirely through transaction fees, aligning their incentives with network usage rather than new issuance.

Anyone can verify the supply cap by running a full node. Your node independently checks every block and every transaction against the consensus rules, including the issuance schedule. If a miner tried to create extra bitcoin, your node would reject the block. This is not trust — it is verification. No other monetary system in history has offered this level of auditability to every participant.

Key Points

• The 21 million cap is a consensus rule enforced by every full node, not a policy decision
• The block reward halves approximately every four years, reducing new supply issuance exponentially
• The last bitcoin will be mined around 2140, after which miners earn only transaction fees
• Anyone running a full node can independently verify the total supply at any time
• This verifiable scarcity is what gives Bitcoin its unique value proposition as sound money