Bitcoin has a fixed supply cap of 21 million coins, hardcoded into its protocol to create digital scarcity similar to gold. If you've wondered when the last bitcoin will be mined, the answer is around 2140. Currently, about 19.9 million bitcoins exist, leaving approximately 1.5 million remaining. This guide explains Bitcoin's supply mechanics, why mining takes over a century to complete, and what happens when all bitcoins are finally mined.
Key Takeaways:
Bitcoin has a fixed maximum supply of 21 million coins hardcoded into its protocol.
The last bitcoin will be mined around the year 2140 due to halving events every four years.
Currently, about 19.9 million bitcoins have been mined, leaving approximately 1.5 million remaining.
Mining rewards halve every 210,000 blocks, progressively slowing new coin creation.
After 2140, miners will rely entirely on transaction fees instead of block rewards.
By 2035, over 99% of all bitcoins will already exist in circulation.
Bitcoin's creator, Satoshi Nakamoto, designed the cryptocurrency with a strict maximum supply of 21 million coins. This creates a deflationary asset that can't be manipulated like traditional fiat currencies. The concept mirrors gold: finite supply helps maintain value over time. New bitcoins are created through mining. Miners use powerful computers to solve mathematical puzzles that validate transactions and secure the network. Every ten minutes, a miner successfully adds a new block and receives newly created bitcoins as reward. As of the 2024 halving, miners earn 3.125 BTC per block. Every 210,000 blocks (roughly four years), the mining reward gets cut in half—an event called "halving." When Bitcoin launched in 2009, miners earned 50 BTC per block. After halvings in 2012, 2016, 2020, and 2024, rewards dropped to 25, 12.5, 6.25, and 3.125 BTC respectively. This pattern continues until the reward reaches zero.
The last bitcoin will be mined around 2140. Understanding why requires examining Bitcoin's halving schedule, which creates an exponential slowdown in new coin creation. Bitcoin's protocol includes 32 halving events, each making mining produce fewer coins until the reward reaches zero.
Currently in 2025, approximately 900 new bitcoins are created daily. After the 2028 halving, this drops to 450 per day. By 2032, it'll be 225 per day. By 2136, miners receive just 0.00000001 BTC per block—a tiny fraction. These final halvings between 2136 and 2140 produce the last remaining satoshis.
The exact date isn't fixed because Bitcoin's network adjusts mining difficulty every two weeks to maintain ten-minute block times. If more miners join with powerful hardware, blocks mine faster and difficulty increases. If miners leave, difficulty decreases. The 2140 estimate could shift by months or years, but won't change dramatically.
Here's the surprising part: while the last bitcoin won't be mined until 2140, most action happens sooner. By 2035, over 99% of all bitcoins will exist. The final 105 years (2035-2140) produce only 0.5% of total supply. Bitcoin's scarcity factor is largely in effect today.
The halving timeline:
2028: Reward drops to 1.5625 BTC
2032: Falls to 0.78125 BTC
2060: Below 0.006 BTC
2136: 32nd halving occurs
~2140: Last satoshi mined
Mining doesn't stop in 2140—the block reward simply hits zero, transitioning entirely to fee-based compensation.
When all 21 million bitcoins are mined in 2140, mining won't disappear—miners will rely entirely on transaction fees paid by users. This transition has been planned from the beginning and represents Bitcoin's most important long-term sustainability question.
Transaction fees work like auctions. Users attach fees to incentivize miners to process their transactions quickly. During high network activity, users pay higher fees for fast confirmations. Currently, fees are a small portion of miners' income compared to block rewards, but this balance will shift by 2140.
Will transaction fees alone maintain Bitcoin's security? The answer depends on several factors. If Bitcoin's value appreciates due to scarcity, even small fees in satoshis could be worth significant amounts. Layer 2 solutions like Lightning Network allow millions of small transactions off-chain, letting the main blockchain focus on high-value transactions where users pay premium fees.
The shift to fee-only mining will cause industry changes. Only efficient miners using renewable energy and advanced hardware will remain profitable, likely causing consolidation. However, Bitcoin's difficulty adjustment ensures blocks continue every ten minutes regardless of miner participation. The environmental impact could be positive as diminishing rewards reduce electricity consumption incentives, pushing miners toward renewable energy sources. By 2140, Bitcoin mining could be predominantly renewable, potentially reducing environmental concerns.
For Bitcoin's store of value role, reaching the 21 million cap reinforces its 'digital gold' narrative. Complete scarcity combined with ongoing demand represents a unique monetary experiment. Bitcoin will become the first major monetary asset with finite, verifiable supply—no gold or fiat currency offers the same combination.
When is the last bitcoin expected to be mined?
The last bitcoin will be mined around the year 2140, though the exact date may vary slightly based on network hashrate changes.
What happens when all 21 million bitcoins are mined?
Miners will continue operating but will earn income exclusively from transaction fees instead of block rewards.
How many bitcoins are left to mine?
Approximately 1.5 million bitcoins remain to be mined as of 2025, representing about 5.2% of the total supply.
When will all the bitcoin be mined?
All bitcoins will be mined by approximately 2140 after the 32nd and final halving event completes.
When will bitcoin be all mined?
Bitcoin mining will reach completion around 2140 when the block reward reduces to zero satoshis.
Will mining stop in 2140?
No, mining will continue after 2140 to process transactions, but miners will only receive transaction fees as compensation.
Can the 21 million bitcoin limit be changed?
Technically possible but practically impossible, as it would require consensus from the majority of the network, which would devalue everyone's holdings.
Bitcoin's journey to mine the last coin in 2140 represents a unique experiment in monetary design. The 21 million supply cap creates digital scarcity that strengthens over time through predictable halving events every four years. Understanding this timeline matters because it shapes Bitcoin's long-term value proposition and helps investors make informed decisions. While most Bitcoin already exists in circulation, the transition to a fee-based mining model will test the network's sustainability. For those interested in participating in this digital revolution, platforms like MEXC make it easy to start trading and learning about Bitcoin today.