The cryptocurrency Bitcoin is a limited and finite supply. That means, there will only ever be 21 million bitcoins ever produced and being able to mine. On average, these bitcoins are introduced to the Bitcoin supply at a fixed rate of one block every ten minutes. 2140 is supposed to be the year, where all Bitcoin is mined. In February 2021 18.638 million bitcoins have been mined, which is equivalent to 88.3% of the maximum supply. So, there are 2.362 million left.
- While there can only ever be a maximum of 21 million bitcoins, because people have lost their private keys or have died without leaving their private key instructions to anybody, the actual number of available bitcoins in circulation could actually be millions less.
- What will miners do when all the Bitcoin has been mined you might wonder. When the circulation supply reaches its maximum, miners will not receive any more block rewards. Instead, they will receive transaction fees. That means they will still be able to interact and participate in the block discovery process, only their reward will be different.
At the moment transaction fees make up a small proportion of a miner’s revenues, since miners currently mint around 900 BTC a day, but earn between 60 and 100 BTC in transaction fees each day. That means transaction fees currently make up as little as 6.5% of a miner’s revenue, but in 2140, that will change to 100%. Which will be a big difference.