Key Takeaways
Bitcoin has a fixed total supply cap of 21 million coins.
As of August 2025, more than 19.91 million BTC have already been mined (approx. 94.8% of the total supply).
With the current block rewards, new bitcoins are mined at a rate of approximately 3.125 BTC every 10 minutes.
When the final bitcoin is mined around the year 2140, miners will no longer receive new BTC as rewards. Instead, they will rely entirely on transaction fees to cover mining costs and sustain the network.
Blockchain analysis firms estimate that up to 20% of Bitcoin’s current circulating supply may be lost or inaccessible.
Introduction
Bitcoin has one of the strictest monetary policies in existence: a hard cap on supply. Only 21 million bitcoins will ever exist. This scarcity is one of the main reasons people compare Bitcoin to gold and treat it as a store of value. But what happens once that cap is reached? How will mining, security, and transactions work when no new coins are created? Let’s break it down.
What Is the Total Supply Cap of Bitcoin?
From the start, Bitcoin’s creator, Satoshi Nakamoto, locked the maximum supply at 21 million. The idea was to build a system immune to the kind of inflation that plagues traditional currencies. Unlike central banks, which can print money endlessly, Bitcoin enforces a fixed limit. This hard limit ensures that no more than 21 million BTC can ever be created, making Bitcoin an inflation-resistant asset.
How Many Bitcoins Have Been Mined?
As of August 2025, about 19.91 million bitcoins have been mined. The mining process began in 2009, but the issuance of new BTC slows every four years due to scheduled halving events, where block rewards are cut in half. Only a little over 1 million coins remain to be mined, and because of the halvings, the very last BTC is expected to be mined around the year 2140.
What if mining computers become more powerful?
Satoshi designed the Bitcoin protocol in a way that ensures blocks are mined, on average, every 10 minutes. If miners use more powerful rigs (or if more miners join the network), the Bitcoin hash rate will increase and the protocol will automatically adjust to make mining more difficult. If miners leave the network, the hash rate goes down, and the protocol makes mining relatively easier. So regardless of the total hash rate, the protocol automatically adjusts to make sure Bitcoin blocks are mined approximately every 10 minutes.
How Long Does It Take to Mine 1 Bitcoin?
Currently, miners earn a reward of approximately 3.125 bitcoins every 10 minutes. This means that, on average, 0.3125 bitcoins are mined per minute across the entire network. To put it another way, one bitcoin is generated roughly every 3.2 minutes when aggregating mining activity globally.
How Many Bitcoins Are in Circulation?
In theory, the current supply of bitcoins in circulation matches the total mined amount, around 19.91 million. But in reality, a significant portion is gone forever. Analysts estimate up to 20% of all mined bitcoins are lost due to misplaced private keys, discarded hard drives, or forgotten crypto wallets. That means the actual usable supply is lower, making Bitcoin even scarcer than the raw numbers suggest.
What Happens to Mining Fees When All BTC Gets Mined?
Once the last bitcoin is mined, block rewards disappear. Miners will then rely entirely on transaction fees to earn revenue. These fees are paid by users whenever they send Bitcoin, and they’ll need to be high enough to keep miners incentivized to secure the network.
There are a few possible outcomes:
Higher transaction fees: Users might face higher costs to move BTC if miners demand more compensation.
More reliance on scaling solutions: Networks like the Lightning Network may help ease congestion and keep fees manageable.
Mining consolidation: If fees aren’t enough, some miners may shut down. Although unlikely, this could raise concerns about network security if it happens on a large scale.
Still, Bitcoin has a track record of adapting, so it’s likely that new solutions will emerge to balance miner incentives and user costs.
Closing Thoughts
The year 2140 is still far away, but the end of new bitcoin issuance is more than just a theoretical milestone. It will test how the network operates when miners depend solely on fees rather than current block rewards. That transition could reshape transaction costs and mining economics.
At the same time, Bitcoin’s hard cap is one of the things that makes it unique. Its fixed supply makes it valuable as a scarce, decentralized asset. Whether fees rise, scaling improves, or new incentives develop, Bitcoin’s future will depend on the same forces that have carried it this far: adaptability, innovation, and trust in a system no single entity controls.
Further Reading
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