When Will the Last Bitcoin Be Mined?

When Will the Last Bitcoin Be Mined?

The last Bitcoin is expected to be mined around the year 2140. This date is determined by Bitcoin's issuance schedule, which was programmed into the protocol by Satoshi Nakamoto at its creation and has operated without modification since the genesis block was mined on January 3, 2009.

Bitcoin's supply schedule follows a precise mathematical formula. Every 210,000 blocks, approximately every four years, the number of new Bitcoin created with each block is cut in half. This event is known as the halving. The initial block reward was 50 Bitcoin. After the first halving in 2012, it dropped to 25. The second halving in 2016 reduced it to 12.5. The third in 2020 brought it to 6.25. The most recent halving in April 2024 reduced it to 3.125 Bitcoin per block.

This halving process continues until the block reward becomes smaller than one satoshi (0.00000001 BTC), at which point no more new Bitcoin can be created. Through approximately 32 halvings over roughly 130 years, the total supply asymptotically approaches but never quite reaches 21 million Bitcoin.

The Mathematics of Bitcoin's Supply Cap

Bitcoin's 21 million cap is not an arbitrary number. It is the mathematical result of the issuance schedule: an initial reward of 50 BTC per block, halved every 210,000 blocks.

The calculation is a geometric series: 210,000 blocks multiplied by 50 BTC, plus 210,000 multiplied by 25, plus 210,000 multiplied by 12.5, and so on. This series converges to exactly 21 million Bitcoin (technically, 20,999,999.9769 BTC due to rounding at the satoshi level).

The current state of this issuance process is well past the midpoint. Over 19.5 million Bitcoin have already been mined, roughly 93% of the total supply. The remaining 7% will be distributed over the next century-plus, with each halving further slowing the rate of new issuance.

This front-loaded issuance schedule means that Bitcoin's scarcity is already extreme and will only increase with each subsequent halving. The stock-to-flow ratio, the relationship between existing supply and new annual production, increases with every halving, making Bitcoin progressively harder money over time.

Why the 21 Million Cap Matters

Saifedean Ammous identifies absolute scarcity as Bitcoin's most revolutionary monetary property. Gold, often called the scarcest monetary commodity, sees its above-ground supply increase by roughly 1.5% annually through mining. Bitcoin's supply increase is currently around 0.8% and will continue to decrease with each halving. Eventually, it reaches zero.

No monetary good in human history has ever had a truly fixed supply. Gold can always be mined. Fiat currency can always be printed. Even digital currencies before Bitcoin, as Nick Szabo explored through his work on bit gold, could not solve the problem of preventing digital scarcity from being undermined by copying.

Satoshi solved this problem through proof of work and decentralized consensus. The 21 million cap is enforced not by any central authority but by every node on the network independently. Changing the cap would require convincing the overwhelming majority of node operators to voluntarily adopt new rules that dilute their own holdings, a near-impossible coordination problem.

This is what makes Bitcoin's scarcity fundamentally different from any imposed scarcity in history. It is not maintained by a ruler's discipline, a central bank's policy, or geological limits. It is maintained by the economic self-interest of every network participant.

What Happens After the Last Bitcoin Is Mined?

A common concern is whether the Bitcoin network can remain secure after the block subsidy disappears. If miners are no longer rewarded with new Bitcoin, what incentivizes them to continue securing the network?

The answer is transaction fees. Even today, miners receive transaction fees in addition to the block subsidy. As the subsidy decreases with each halving, transaction fees are expected to comprise an increasingly large percentage of miner revenue. By the time the last Bitcoin is mined in approximately 2140, transaction fees will be the sole source of miner compensation.

This transition is gradual by design. Each halving provides the market with decades of data about how the fee market develops as the subsidy decreases. The Bitcoin network has more than a century to optimize this transition, and each halving brings more data about how the fee market responds to reduced subsidy.

Parker Lewis has argued that the concern about post-subsidy security fundamentally misunderstands Bitcoin's value proposition. If Bitcoin succeeds as a global monetary standard, the value of the network will be enormous, and the fees required to secure it will be proportional to that value. The fee market will reflect the economic significance of Bitcoin settlement, just as the current mining market reflects the value of newly minted Bitcoin.

Lost Bitcoin and Effective Supply

While 21 million is the maximum number of Bitcoin that can ever exist, the effective circulating supply is lower. Bitcoin that is permanently inaccessible, due to lost private keys, lost hardware, or the coins attributed to Satoshi Nakamoto that have never moved, reduces the available supply.

Estimates of permanently lost Bitcoin vary widely, but commonly cited figures suggest that between 3 and 4 million Bitcoin may be permanently inaccessible. This means the effective supply cap may be closer to 17 or 18 million coins, making Bitcoin even scarcer than its nominal cap suggests.

This dynamic creates an interesting property: Bitcoin's effective supply can decrease over time but can never increase. Lost Bitcoin is lost forever. There is no mechanism to recover or replace it. This one-way ratchet makes Bitcoin deflationary in the most literal sense.

Bitcoin's Supply Cap and Sound Money

The Austrian school of economics has long argued that sound money must be resistant to supply manipulation. Every historical example of monetary debasement, from Roman coin clipping to modern quantitative easing, involved expanding the money supply at the expense of existing holders.

Bitcoin's fixed supply cap is the most robust defense against debasement ever created. It does not rely on political restraint, institutional discipline, or physical scarcity. It relies on mathematical certainty and decentralized enforcement.

Ammous frames this as the fundamental innovation: for the first time in human history, a monetary good exists whose supply schedule is completely known in advance and cannot be changed. Every individual who acquires Bitcoin knows exactly what percentage of the total supply they hold, both now and at any point in the future. This certainty is unprecedented in monetary history.

Securing Your Share of 21 Million With Onramp

With over 93% of all Bitcoin already mined and the rate of new issuance decreasing with every halving, the window for accumulating Bitcoin at today's scarcity levels is narrowing. Each day, approximately 450 new Bitcoin enter circulation. After the next halving, that number drops to roughly 225.

Onramp Bitcoin provides the infrastructure for acquiring and securing a position in this finite monetary asset. Through Multi-Institution Custody across BitGo, Coinbase, and Anchor Watch, Onramp secures over $1 billion in client assets with the knowledge that every satoshi held represents a permanent fraction of the 21 million supply cap.

Whether through dollar-cost averaging on Onramp's brokerage, tax-advantaged accumulation via Bitcoin IRA, or institutional custody, Onramp provides the pathways for securing your share of the 2.1 quadrillion satoshis that will ever exist.

Frequently Asked Questions

When will the last Bitcoin be mined?

The last Bitcoin is projected to be mined around the year 2140, when the block reward becomes smaller than one satoshi after approximately 32 halvings. Currently, over 19.5 million of the 21 million total Bitcoin have already been mined, with the remaining supply distributed over the next century-plus through decreasing block rewards.

What happens when all 21 million Bitcoin are mined?

When all Bitcoin are mined, miners will be compensated exclusively through transaction fees rather than block rewards. This transition is gradual, with each halving reducing the subsidy while the fee market develops. The network has over a century to optimize this transition, and fees are expected to reflect Bitcoin's value as a global settlement network.

Can the 21 million Bitcoin cap be changed?

Changing the cap would require the overwhelming majority of node operators to voluntarily adopt new rules that dilute their own holdings, which is an effectively impossible coordination problem. The cap is enforced by every node independently, not by any central authority. This decentralized enforcement makes Bitcoin's scarcity uniquely robust.