Bitcoin has a hard limit: only 21 million bitcoin will ever exist. That number is not a marketing line or a rough approximation. It is written into the software every node runs, and it has been fixed since the first block was mined in January 2009. As of this writing, roughly 20.1 million of those bitcoin have been mined, about 95.7% of the total, and the rest is scheduled to trickle out over the next 113 years. For Canadians deciding whether to buy, the cap matters for one reason above all others: it is the one part of the Bitcoin thesis that nobody can quietly change to make the asset look better. Here is how the supply schedule actually works, when the last bitcoin gets mined, and what the cap does and does not tell you about price.

Table of Contents

• 21 Million Bitcoin: What the Supply Cap Actually Is
• How the Bitcoin Supply Cap Works Block by Block
• When the Last Bitcoin Will Be Mined
• Does the 21 Million Cap Decide the Price?
• Buying Bitcoin in Canada and Keeping the Records
• Frequently Asked Questions

21 Million Bitcoin: What the Supply Cap Actually Is

The cap is arithmetic, and anyone can check it. Bitcoin divides one coin into 100,000,000 units called satoshis, and new satoshis are handed to miners as a reward for sealing each block. The first reward was 50 bitcoin. Every 210,000 blocks, that reward halves: 50, then 25, then 12.5, then 6.25, then 3.125. Add up every halving until the reward falls below one satoshi and you land on 20,999,999.9769 bitcoin. The number gets rounded to 21 million because the fraction is trivial and the rounding is traditional. The arithmetic is not approximate.

Satoshi Nakamoto set that schedule in the genesis block, the first entry in the chain, and the original Bitcoin whitepaper describes the halving as the mechanism that makes the total finite. There was no board of directors and no central bank to appeal to. The rule lives in code that every participant independently agreed to run, which is why it has survived more than a decade of people trying to find a reason to change it.

One clarification worth making early, because it comes up constantly: 21 million is the maximum ever created, not the amount in circulation. Bitcoin sitting in a wallet nobody has touched since 2014 is not spendable. The number of coins actually reachable right now is lower than 21 million, and it will stay lower.

How the Bitcoin Supply Cap Works Block by Block

The chain is at block 973,134 as of this writing, which puts it in the middle of the fifth halving epoch. Each epoch spans 210,000 blocks and each block currently pays a miner 3.125 bitcoin. The next halving arrives at block 1,050,000, roughly 76,866 blocks away. At the pace of about ten minutes per block that lands in April 2028, and the reward drops to 1.5625 bitcoin per block.

Here is the part that surprises people. Once that halving happens, the total mined climbs to 20,343,750 bitcoin, which leaves only 656,250 bitcoin that will ever be created after it. The final stretch of the schedule is not a slow drip. It is a rounding error spread across a century and a half. The Bitcoin halving aftermath in 2026 covers what the most recent halving did to miner economics and market supply.

The halving date is not a fixed appointment. Difficulty adjusts every 2,016 blocks to hold block production near ten minutes, so if miners turn machines off, blocks slow and the halving drifts later. In practice halvings have arrived roughly every four years, with the date moving a few months each time as hash rate and block times change. The Bitcoin developer guide documents the subsidy schedule and the adjustment rules if you want to work through the mechanics directly.

When the Last Bitcoin Will Be Mined

The final satoshi is scheduled for block 6,930,000, and there are nearly 5.96 million blocks left to mine. At the current rate of roughly 52,600 blocks a year, that puts the last bitcoin somewhere around 2140. The number moves as hash rate moves, so treat it as a generation rather than a date. The closer milestone is firmer: 99% of the 21 million will be mined by roughly February 2035.

Look at what happens in the back half of the schedule. The final century of mining, from about block 1,670,400 onward, produces roughly 85,800 bitcoin in total, which is 0.4% of the entire supply. That is about 191 days of mining at the current rate of 450 bitcoin a day, spread across a hundred years. The last full epoch of 210,000 blocks pays one satoshi per block, so the whole epoch yields 0.0021 bitcoin. The epoch before that pays twice as much and adds 0.0042.

You can watch the remaining count tick down in real time on mempool.space, which shows current block height and the mined total. One more point about forks: a fork creates a separate chain with its own supply schedule and its own rules. Thousands of altcoins exist because the 21 million limit applies to Bitcoin, not to the family of chains descended from its code. Bitcoin Cash, for instance, dropped the 21 million limit when it forked in 2017 and has no fixed maximum supply.

Does the 21 Million Cap Decide the Price?

No. The cap is a fixed quantity, and a fixed quantity on its own does not set a price. Scarcity is a necessary condition for the store-of-value argument, not a sufficient one. Demand is the variable, and demand for Bitcoin has moved in ways nobody predicted in 2009, which is a fair reason for humility about any forecast built on the cap alone.

Two further complications matter. The first is the gap between coins created and coins available. Published estimates of permanently unreachable coins commonly land between about 2 million and 3.7 million bitcoin, depending on assumptions about dormant wallets and lost seeds. The effective scarcity of Bitcoin is therefore lower than the headline number and nobody can measure it precisely.

The second is that owning bitcoin is not the only way to hold exposure to it. Exchange-traded funds, futures and structured products give people a claim on price without a coin existing in their wallet. Those instruments add demand for Bitcoin without adding to circulating supply, which cuts both ways depending on which way prices move.

What the cap does give you is a rule nobody can inflate. A central bank can expand its money supply on a schedule it chooses. No group can do that to Bitcoin without a consensus change that would split the chain and likely destroy most of the value it was trying to create. That is a real property, and it is also the whole of it. Anyone selling you a guaranteed return tied to the 21 million number is selling you something the cap does not promise.

Buying Bitcoin in Canada and Keeping the Records

Scarcity is the reason people show up. The purchase itself is mechanical, and the mechanics are what actually determine what you pay. At a physical machine the rate you get depends on the operator’s spread and fees rather than on the block subsidy, so the cost of buying a fraction of a bitcoin has nothing to do with how much of the 21 million has been mined. Our guide to buying Bitcoin with cash in Canada walks through what a cash purchase actually involves, including ID requirements and the limits that apply to larger amounts.

If you are buying in person, the Bitcoiniacs ATM locations page lists every current machine with its address and hours. Buy from an operator that asks for identification. The ID check is not friction to be worked around, it is the thing that separates a registered business from a stranger on a messaging app.

Then keep the paperwork. Buying and holding Bitcoin is not a taxable disposal, so nothing is owed when you buy. Disposing of it is, and that is when the file matters. Retain the CAD amount you paid, the amount of bitcoin you received, the quoted rate, every fee charged, the timestamp, your wallet address, the transaction ID and your bank statement. The complete Canadian crypto tax guide covers how the CRA treats acquisition costs and disposal events, and the CRA’s own guidance on valuing crypto-assets sets out how the agency expects the value determined.

One warning, because this topic attracts them: nobody legitimate will ask for your seed phrase, your one-time codes, or a fee paid to an address they sent you. Nobody legitimate will create urgency about a price window. If any of that shows up, you are talking to a thief, and the cap means nothing to them.

Frequently Asked Questions

Why can’t we just create more than 21 million bitcoin?

Because the creation schedule is written into the consensus rules that every node verifies. Adding coins would mean changing what the network agrees is valid, which needs overwhelming agreement from the people running it. A minority that disagrees simply runs the old rules on a new chain, and the value does not transfer. The cap holds because changing it costs everyone, not because of any central authority enforcing it.

Can the 21 million Bitcoin supply cap ever be changed?

Technically yes, and it has been discussed repeatedly. A change would require a coordinated software update accepted by nearly all nodes and miners, and even then the chain would likely split, leaving two competing chains and two different supplies. The practical answer is that the cap is one of the most expensive things in the network to change, which is the same as saying it will not change for any reason short of catastrophic failure.

What happens when there is no Bitcoin left to mine and wallets keep getting lost?

The cap is a maximum ever created, so lost coins do not get reissued. They leave the circulating supply permanently, which means the effective supply keeps falling below 21 million. This is why the often-quoted figure of lost bitcoin is so large, and why nobody can tell you the true circulating number with confidence. It also means the last bitcoin will not be mined in the sense of being handed to someone: the final satoshis will go to whoever is mining in 2140, and whatever has not already been lost will still be sitting in wallets by then.

When will the last Bitcoin be mined?

Block 6,930,000 is the target, and at the current pace of roughly 52,600 blocks a year that is around 2140, with the estimate moving as hash rate moves. The firmer milestone is 99% of the supply, which arrives around February 2035. Over the final century of mining the network produces roughly 85,800 bitcoin in total, so the schedule effectively ends long before the calendar does.

Is there any validity to the BTC scarcity argument?

It holds up as a description of the protocol and gets weaker as a price argument. The supply limit is real, verifiable and cannot be changed without consensus. Whether that limit translates into value depends on demand, which has no fixed schedule and has surprised people in both directions. Read the cap as a fact about the rules rather than as a forecast, and it becomes useful instead of misleading.

The cap is the part of Bitcoin you do not have to take anyone’s word for. It is checkable, it is enforced by the code, and it is why roughly 95.7% of the supply already exists. What you pay for your bitcoin depends on much more ordinary things: the spread and fees where you buy, the rate you get quoted, and the records you keep when you sell. Get those right and the scarcity argument does the rest on its own.