Bitcoin is designed to be a scarce digital asset, but exactly how limited is its supply? In this in-depth blog post, we’ll take a close look at the total number of bitcoins in existence and peel back the layers on how the supply is slowly disbursed over time.
Understanding the controlled supply of Bitcoin is key to assessing its value as a cryptocurrency and investment asset. We’ll address important questions like
- How many bitcoins exist right now?
- How many total bitcoins will there eventually be?
- How is the supply released over time?
- Who receives the new bitcoins created?
- What happens when the supply cap is reached?
- Will the supply cap remain fixed forever?
Join me as we explore the fascinating world of Bitcoin’s limited issuance and supply schedule.
How Many Bitcoins Exist Today?
As of January 2024, there are around 19 million bitcoins in existence. The exact figure is 19,134,437 BTC as of this writing.
New bitcoins are created and added to the total supply every 10 minutes when new blocks are mined. We’ll discuss this process shortly.
The 19 million coins presently in circulation represent over 90% of the total supply that will ever exist. Per Bitcoin’s design, the total eventual supply is limited to 21 million BTC.
At today’s market value of roughly $20,000 per bitcoin, the 19 million bitcoins in existence represent over $380 billion worth of value at the time of writing.
What Determines the Supply of Bitcoin?
Unlike fiat currencies that can be printed without limit, Bitcoin’s total supply is governed by mathematical algorithms built into its code. Specifically, the supply schedule is controlled by:
- Bitcoin Halving – Occurs every 210,000 blocks mined or roughly every 4 years. Reduces the block reward (and thus BTC created) by 50%.
- Block generation – New blocks are added to the blockchain every 10 minutes by miners.
- Block rewards – The reward miners receive for adding blocks. Started at 50 BTC, now 6.25 BTC after 3 halvings.
- Supply cap – There will eventually be a maximum of 21 million bitcoins.
This system creates a “controlled supply” that increases the number of bitcoins at a predictable rate up to the cap. Next we’ll look closer at how it works.
The Distribution of New Bitcoins Over Time
When Bitcoin first launched in 2009, the block reward that miners received for creating a new block on the blockchain was 50 BTC.
At Bitcoin’s launch, blocks were generated quickly, earning miners 50 new BTC every 10 minutes. This allowed the first 2.625 million bitcoins to be mined in less than a year.
But Bitcoin’s code included programmed halving events every 210,000 blocks. Each halving cuts the block reward in half. Here is the schedule:
- November 28, 2012 – 1st halving from 50 BTC to 25 BTC
- July 9, 2016 – 2nd halving from 25 BTC to 12.5 BTC
- May 11, 2020 – 3rd halving from 12.5 BTC to 6.25 BTC
Halving events dramatically slow the growth of new bitcoins added to the network. While nearly 2.7 million bitcoins were mined in the first year, the next 2.7 million took 4 years, and the 2.7 million after that took another 4 years.
Today’s block reward of 6.25 BTC translates to just 900 new bitcoins being added to the supply each day. At that rate, it will take over 100 years for the remaining 2 million BTC to enter circulation.
This controlled supply through block rewards is how all new bitcoins are initially distributed. The first transaction in each new block pays the mining reward, allowing miners to sell these coins on the open market.
What Happens When All 21 Million Bitcoins Are Mined?
Per Bitcoin’s supply algorithm, the last of the 21 millionth bitcoin will be mined somewhere around the year 2140.
When the total cap is reached, there will be no more block rewards for miners. At that point, it is presumed transaction fees from payments will incentivize miners to keep verifying the blockchain.
The supply will remain capped forever after 2140. This hard limit represents a major distinction from fiat currencies, which can always be further inflated.
Some wonder what will happen if most bitcoins are lost before the cap is reached. In theory, developers could release updates to Bitcoin’s protocol to allow further minting. However, this remains highly speculative.
Final Thoughts
One of Bitcoin’s most distinct and intelligent design features is its controlled supply that cannot be altered at whim like fiat currencies. The code dictates how many new BTC are released over time through mining, leading to the fixed cap of 21 million.
This disbursement through block rewards and halving events leads to a fair, measurable distribution where inflation is predictable and the ultimate supply is fixed and scarce.
