Bitcoin's total supply is 21 million, and it's hardcoded in the code—it can't be changed. But you might not know that these 21 million coins can never actually be fully mined. You think mining stops when the reward hits zero? Wrong! The halving reward every four years is like pouring out half a glass of water each time—there's always a little left. Mathematically, this is called an infinite geometric series with diminishing terms. The total seems to approach 21 million, but it will always fall short. Even when the smallest unit, a 'satoshi,' can no longer be divided, it only gets closer to zero—it will never hit zero. Some people worry that fewer rewards will mean no one will mine anymore. In 2025, miners will still be earning 3.125 BTC in rewards, making $350,000. Right now, the entire network's hash rate is powered by 5 million supercomputers—who would do it if it wasn’t profitable? Plus, miners can rely on transaction fees to survive in the future. As long as people use Bitcoin, mining won’t stop, and new coins will keep being generated. And let’s not forget the large number of Bitcoins that have permanently 'disappeared' due to lost private keys. The actual circulating supply is already much lower. Even by 2140, when new supply becomes negligible, the total won’t reach 21 million. We won’t see the so-called 'end of mining' in our lifetime.