How Many Bitcoins Are There, and What Happens After 21 Million Are Mined?

How many bitcoins are there? More than 20 million bitcoins have been mined. The network passed the 20 million mark in March 2026, and the protocol caps the total at 21 million BTC, so fewer than 1 million remain to be issued. The last of them will arrive slowly. Issuance halves roughly every four years, and the final fraction of a coin is not expected until around 2140. Once issuance stops, no new bitcoin is created, and miners are paid only through transaction fees.

Where the 21 million limit comes from

Satoshi Nakamoto, the pseudonymous creator of Bitcoin, did not write “21 million” as a fixed number. The cap is the result of two rules built into the software:

1. Block reward. Every new block lets the miner who produced it create a set number of new coins. When the network launched in 2009, that reward was 50 BTC.
2. Halving interval. Every 210,000 blocks, the reward is cut in half. At an average of one block every 10 minutes, 210,000 blocks takes about four years.

Each four-year period, called an epoch, issues half as many coins as the one before it. Add up 10.5 million + 5.25 million + 2.625 million and so on, and the sum approaches 21 million without exceeding it.

The cumulative column assumes every block claimed its full reward, which is not quite what happened (see below). It shows how front-loaded the schedule is: half of all bitcoin was issued in the first four years, and by the end of the current epoch about 96.9% of the maximum supply will exist. That is why the last few percent take more than a century.

The dates in the table are approximate because blocks do not arrive on a fixed clock. Every 2,016 blocks, the difficulty adjustment makes mining harder or easier so blocks keep arriving about every 10 minutes as computing power changes. Halvings are tied to block height, not calendar dates, so one can land a few weeks earlier or later than a four-year count suggests.

Why the final total will fall just short of 21 million

Bitcoin’s smallest unit is the satoshi, equal to 0.00000001 BTC (one hundred-millionth of a bitcoin). Block rewards are calculated in satoshis, and a satoshi cannot be divided.

When the reward halves, the software uses a bit-shift operation, which discards any remainder. 50 BTC is 5,000,000,000 satoshis, which halves into whole numbers for many rounds. Later the reward becomes an odd number of satoshis, and each halving drops half a satoshi. Those dropped fractions add up, so the issuance limit works out to roughly 20,999,999.98 BTC rather than an even 21 million.

Two other details pull the real total slightly lower still:

• The genesis block. The 50 BTC reward in the very first block, mined in January 2009, cannot be spent under Bitcoin’s rules. Many supply counts still include it.
• Unclaimed rewards. A miner can claim less than the full reward a block allows, but can never claim more. Satoshis left unclaimed are not reissued later. A small number of blocks in Bitcoin’s history did this.

How many bitcoins have been mined, and how many are left

With fewer than 1 million BTC left to issue, the pace of new supply at the current reward can be estimated with simple arithmetic:

• Blocks per day: 24 hours × 6 blocks per hour = about 144 blocks (assumes the 10-minute average holds)
• New BTC per day: 144 × 3.125 = about 450 BTC
• New BTC per year: 450 × 365 = about 164,000 BTC

After the 2028 halving, these figures drop to about 225 BTC a day, and the remaining coins come out in ever smaller amounts through the 2130s.

Max supply, total supply and circulating supply

Crypto data pages usually show three supply numbers, and they answer different questions.

• Max supply is the most that can ever exist under the protocol: 21,000,000 BTC.
• Total supply and circulating supply count coins already issued. For bitcoin, the two are nearly identical because there are no locked team allocations or unvested tokens. All bitcoin entered circulation through mining. Small differences between the two reflect how a data provider defines each metric.
• Fully diluted value (FDV) multiplies the price by a supply figure to count all coins. For bitcoin it is close to the circulating value because most of the supply already exists.

None of these numbers measures how many coins are usable. Coins whose owner lost the private keys, or died without passing on access, cannot be moved but still count in the supply. Spendable bitcoin is therefore lower than the circulating figure by an amount nobody can measure precisely.

How long it takes to mine one bitcoin

Across the whole network, one new bitcoin is created about every 3.2 minutes at the current reward: 10 minutes per block divided by 3.125 BTC per block. Coins arrive in a single chunk of 3.125 BTC when a block is found, paid with that block’s fees to the miner or mining pool that found it.

For an individual miner, the answer depends on their share of the network’s computing power, or hashrate. A miner with 0.01% of it would, on average, win about one block every 70 days at 144 blocks a day. Results swing widely around that average, which is why most miners join pools that share rewards in proportion to work contributed. How Bitcoin mining works covers hardware and electricity costs.

Each halving doubles the network-wide time per coin. After 2028 it becomes about 6.4 minutes per BTC, assuming 10-minute blocks.

When the last bitcoin will be mined

The reward keeps halving until it rounds down to zero. Starting from 5 billion satoshis, the reward shrinks to a single satoshi after 32 halvings. The 33rd halving takes it to zero. The 2024 halving was the fourth, so 29 more remain.

That last halving falls at block 6,930,000 (33 × 210,000). At 10 minutes per block, reaching that height from 2009 takes about 132 years, which is where the commonly cited year of 2140 comes from. Because the difficulty adjustment keeps pulling the average back toward 10 minutes, the date is unlikely to drift by decades.

In practical terms, issuance becomes negligible long before 2140. By the mid-2030s, yearly issuance is a small fraction of 1% of the total.

How we know no more bitcoin can be added

The supply limit is enforced by every full node, the computers that independently check the blockchain. When a miner publishes a block, each node verifies that the reward claimed does not exceed what the schedule allows for that block height. A block that pays itself too much is invalid, and nodes reject it no matter how much computing power produced it.

Raising the cap would mean changing those consensus rules, and the change would only take effect if the people running nodes adopted the new software. Anyone keeping the existing rules would treat the higher-supply chain as a separate network. The cap is not impossible to change, but no single developer, company or group of miners can impose a change.

What happens after all bitcoins are mined

The network keeps running. Transactions are still grouped into blocks, and miners still compete to add them. The difference is what miners get paid.

Today, each block pays the miner two things: the block subsidy (the newly created coins) and the fees attached to the transactions in that block. As the subsidy shrinks toward zero, fees become a larger share of miner income. After the final halving, they are the only income. Nakamoto’s original white paper described this transition, with fees taking over once a set number of coins had entered circulation.

What fees will look like by then is an open question, and it depends on how bitcoin is used:

• If bitcoin is used mainly as a store of value, the base chain might process fewer but larger transactions, which could pay meaningful fees.
• If everyday payments move to layer-2 systems such as the Lightning Network, those payments are settled on the main chain periodically, and each settlement pays a base-layer fee.
• If fee income stays low, fewer miners may operate, reducing the hashrate securing the network. The difficulty adjustment would keep blocks arriving about every 10 minutes, but with less computing power behind them.

Holders would see no change in the coins they own. The fixed supply would simply stop growing.

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