How many Bitcoins have been mined?
As of the time of writing, about 19.8 million bitcoins have been successfully mined, accounting for 94.3% of the total. The remaining 1.2 million bitcoins are expected to be fully mined in the next 17 years. The current overall distribution is shown in the figure below:
As the amount of mineable resources decreases, the difficulty of mining will continue to rise, the demand for computing power will increase, and the mining income will further decline.
What is the total supply of Bitcoin?
How many bitcoins have been mined? The total supply of Bitcoin is set at 21 million, which is a finite number and cannot be produced indefinitely. According to the latest statistics, as of December 2024, about 19.8 million bitcoins have been successfully mined, accounting for 94.3% of the total supply. In other words, there are about 1.2 million bitcoins left to be mined. The maximum supply of Bitcoin is 21 million, and about 19.8 million bitcoins have been mined so far. The mining process of the remaining bitcoins to be mined is achieved through mining. Mining refers to the use of computer computing power to solve an extremely complex mathematical problem. The first miner to solve the problem will receive a certain number of Bitcoins as a reward. As time goes by, the difficulty continues to increase, and more powerful computing power is required to obtain Bitcoin rewards.
It is important to note that the issuance of Bitcoin is released according to a pre-defined issuance curve, halving approximately every four years. Initially, a reward of 50 Bitcoins was granted for solving a block, which halved to 25 Bitcoins in 2012, to 12.5 Bitcoins in 2016, and to 6.25 Bitcoins in 2020. It is expected to halve again in 2024 to 3.125 Bitcoins. This issuance mechanism aims to control inflation and ensure the scarcity of Bitcoin. As the remaining Bitcoin to be mined decreases, the difficulty of mining will continue to increase, and rewards will gradually decrease until the last Bitcoin is mined around 2140. Therefore, the quantity of Bitcoin being mined is gradually approaching its predetermined upper limit.
How does the difficulty of Bitcoin mining change over time?
The changes in Bitcoin mining difficulty directly affect the speed at which Bitcoin is mined. The Bitcoin network is designed to produce a new block every ten minutes to maintain stable system operations. To achieve this goal, the difficulty of Bitcoin mining automatically adjusts according to changes in computing power. The difficulty of Bitcoin mining adjusts automatically every 2016 blocks. As more miners join, the difficulty continues to rise. The difficulty adjustment mechanism ensures that one block is produced approximately every ten minutes. Specifically, if the time taken to produce the first 2016 blocks is less than 20160 minutes, it indicates that the computing power is too high, and the system will increase mining difficulty to extend block production time. Conversely, if the block production time exceeds 20160 minutes, the system will lower the mining difficulty to speed up the block production rate. This dynamic adjustment mechanism keeps the issuance rate of Bitcoin at about one block every ten minutes.
As more miners join the mining ranks, the overall network's computing power continues to increase, leading to a corresponding rise in mining difficulty. According to statistical data, the difficulty of Bitcoin mining has risen from 1 at the genesis block in 2009 to over 4 trillion by May 2023, an astonishing increase of over 400 billion times. The continuous rise in difficulty means that the cost of computing power required to mine one Bitcoin is also increasing. In the early days, it was easy to mine with an ordinary computer, but now it can no longer meet the computing power demands for mining; specialized mining equipment and large-scale mining farms are now necessary to obtain considerable profits. The automatic adjustment mechanism of Bitcoin mining difficulty ensures stable issuance of Bitcoin while also reflecting the degree of Bitcoin mining. As the remaining amount available for mining decreases, the mining difficulty will continue to rise, making it a more practical choice for ordinary users to join mining pools and share profits.
What is the Bitcoin mining reward mechanism?
The Bitcoin mining reward mechanism directly determines the speed and total amount of Bitcoin mined. This mechanism aims to control the issuance of Bitcoin and maintain its monetary properties. A certain amount of Bitcoin reward can be obtained for each successful mining of a new block. The reward amount is halved every four years. Currently, the reward is 6.25 Bitcoins per block. Specifically, every time a miner solves a cryptographic puzzle to create a new block with their computing power, they can receive a certain amount of Bitcoin as a reward. The initial reward was 50 Bitcoins per block, which is halved every four years, and the current reward is 6.25 Bitcoins per block. The halving cycles of the reward amount are as follows:
2009-2012: 50 Bitcoins per block.
2012-2016: 25 Bitcoins per block.
2016-2020: 12.5 Bitcoins per block.
2020-2024: 6.25 Bitcoins per block.
2024-2028: Expected to be 3.125 Bitcoins per block. This reward mechanism causes the issuance of Bitcoin to decrease exponentially, approaching but never exceeding the upper limit of 21 million Bitcoins. As time progresses, rewards will become fewer, and the speed at which Bitcoin is mined will also slow down.
It is worth mentioning that, in addition to block rewards, miners can also earn transaction fees as additional income. As the usage of Bitcoin increases, transaction fees may become the primary source of income for miners, thus delaying the downward trend of mining profits. The Bitcoin reward mechanism maintains its value by strictly controlling the issuance, while also determining the pace and upper limit of Bitcoin mining. This design gives Bitcoin a very high degree of scarcity and anti-inflation capability.
How does Bitcoin block reward halve over time?
The halving mechanism of Bitcoin block rewards directly affects the speed at which Bitcoin is mined. This mechanism is embedded in Bitcoin's code and is executed automatically every four years, halving the block rewards.
The first halving occurred in 2012, reducing the reward from 50 to 25 Bitcoins.
Halved again to 12.5 Bitcoins in 2016.
In 2020, the reward was halved to 6.25 Bitcoins, with the next halving expected around 2024. This design of halving rewards aims to control the issuance of Bitcoin and avoid inflation. As the rewards gradually decrease, the speed at which Bitcoin is mined will also slow down until it reaches the total limit of 21 million Bitcoins around 2140.
2009-2012: Reward of 50 Bitcoins per block.
November 28, 2012: First halving, reward reduced to 25 Bitcoins.
July 9, 2016: Second halving, reward reduced to 12.5 Bitcoins.
May 11, 2020: Third halving, reward reduced to 6.25 Bitcoins.
2024: Fourth halving, reward will be reduced to 3.125 Bitcoins. Following this pattern, it is expected that the reward will halve again to 1.5625 Bitcoins in 2028, and then continue to halve every four years until the last Bitcoin is mined around 2140. It is important to note that as block rewards gradually decrease, the proportion of transaction fees in miners' income will increase. In the future, transaction fees may become the primary source of miners' income. As the amount available for mining decreases, the difficulty of mining will continue to rise, and the demands for computing power will increase. The halving mechanism of Bitcoin block rewards is key to controlling the issuance of Bitcoin, directly determining the pace and upper limit of Bitcoin mining, thus maintaining its monetary properties and value stability.
What is the trend of Bitcoin mining profits over time?
The trend of Bitcoin mining profits is closely related to the quantity of Bitcoin mined. In the early days, due to low computing power, mining profits were extremely high. As more and more miners joined, the computing power and difficulty continued to increase, leading to a gradual decrease in profits. Early mining profits were extremely high and decreased with increasing difficulty. Professional mining farms use high-end computing equipment to maintain certain profits. Individual mining yields are meager, and joining a mining pool for dividends is more practical. Looking back at the development history of Bitcoin, initially, due to the small number of participants, one could obtain considerable Bitcoin rewards using ordinary computers. From 2009 to 2012, the reward for each block was 50 Bitcoins, and the mining profits at that time were very attractive. Subsequently, more and more miners flooded in, and the computing power and difficulty began to rise rapidly, while the rewards were gradually halved, leading to a significant drop in single-machine mining profits. To maintain a certain profit rate, miners had to invest more computing power, use specialized mining equipment, and establish large-scale mining farms.
Today, Bitcoin mining has become highly specialized and centralized. The top ten mining pools globally control the vast majority of the computing power, making it difficult for ordinary individual users to obtain considerable profits. Data shows that currently, mining with a home computer may yield only a few dollars in a year. Therefore, for ordinary users, joining a mining pool and sharing profits is a more practical choice. Mining pools can stabilize block rewards by concentrating computing power and divide the rewards among the miners in the pool based on their contributed computing power. It is noteworthy that as the number of Bitcoins available for mining decreases, mining profits will further decline. In the future, transaction fees may become the primary source of income for miners. At the same time, the emergence of new mining algorithms may completely change the existing mining model.
As of now, approximately 18.8 million Bitcoins have been successfully mined, accounting for 94.3% of the total supply. The remaining 1.2 million Bitcoins are expected to be fully mined within the next 17 years. As the amount available for mining decreases, mining difficulty will continue to rise, and the demands for computing power will increase, leading to a further decrease in profitability.
How is the concentration of Bitcoin mining distributed?
The concentration of Bitcoin mining directly affects the speed at which Bitcoin is mined and the degree of decentralization. Currently, global Bitcoin mining activities are highly concentrated in a few countries and mining pools. Countries like China, the United States, and Kazakhstan have the highest shares of mining power. The top ten mining pools control the majority of the network's computing power, affecting the degree of decentralization. According to statistical data, China, the United States, and Kazakhstan are the three countries with the most concentrated Bitcoin mining power, collectively accounting for nearly 70% of the total network power. Among them, Chinese mining farms contribute about 65% of the global computing power, leading by a wide margin. In addition to geographical concentration, Bitcoin mining also shows high centralization in pool operations. Data shows that the current top ten mining pools control the vast majority of the computing power of the Bitcoin network, including:
AntPool
F2Pool
ViaBTC
BTC.com
Poolin
Binance Pool
Huobi Pool
OKEx Pool
SlushPool
BTCC Pool
These large mining pools, by concentrating computing power, can stabilize their acquisition of block rewards and thus dominate the entire Bitcoin mining process. This high level of centralization undoubtedly affects the essential characteristic of Bitcoin as a decentralized cryptocurrency. Theoretically, if any single entity can control more than 51% of the network's computing power, it could potentially manipulate transaction records, conduct double-spending attacks, etc. The reality is that there are also checks and balances among these large pools and mining farms, making it difficult for any single entity to dominate. At the same time, as the difficulty of Bitcoin mining continues to increase, the degree of centralization may gradually decrease. The high degree of centralization in Bitcoin mining reflects that its decentralization characteristics have been affected to some extent, but due to the existence of internal checks and balances, it is unlikely to be completely controlled and manipulated by any single entity in the short term.
How significant is the environmental impact of Bitcoin mining?
Bitcoin mining has certain negative impacts on the environment, mainly manifested in massive energy consumption and carbon emissions. As the quantity of Bitcoin mined continues to increase, this impact is also becoming more pronounced. Huge electricity consumption leads to carbon emissions and energy waste; some mining farms use renewable energy to reduce environmental impacts. New mining algorithms may significantly lower energy consumption. According to estimates by research institutions, the annual electricity consumption of Bitcoin mining reached 127.46 terawatt-hours in 2022, equivalent to Argentina's total electricity consumption for a year. Such enormous electricity consumption not only causes a significant waste of energy but also results in approximately 59 million tons of carbon dioxide emissions annually, primarily relying on fossil fuels for power generation.
In pursuit of higher mining profits, some large mining farms choose to concentrate their construction in areas with low electricity prices, further exacerbating local energy consumption and environmental pressure. For example, places like Texas in the United States and Kazakhstan have attracted a large number of mining farms. Some mining farms have also begun to utilize renewable energy sources such as hydro, wind, and solar power to reduce their environmental impact. For instance, some hydroelectric power stations in Quebec, Canada provide cheap green electricity to nearby mining farms. The Bitcoin community is also actively seeking new mining algorithms in hopes of significantly reducing energy consumption. For example, the 'RandomX' algorithm under development is expected to reduce energy consumption by more than 60%. Once the new algorithm is widely adopted, it will help alleviate the heavy pressure that Bitcoin mining places on the environment. As of now, approximately 18.8 million Bitcoins have been successfully mined, accounting for 94.3% of the total supply. The remaining 1.2 million Bitcoins are expected to be fully mined within the next 17 years. As the amount available for mining decreases, mining difficulty will continue to rise, further increasing the demand for computing power and energy, which may further exacerbate environmental impacts. Therefore, while Bitcoin continues to be mined, how to control its impact on the environment will be a major issue that urgently needs to be addressed, requiring collaboration among the mining industry, regulatory agencies, and the technology community to jointly seek feasible solutions.
What is the future outlook for Bitcoin mining?
As the number of Bitcoins mined continues to increase, the future outlook for mining is also becoming increasingly concerning. In fact, the profits and models of Bitcoin mining may undergo significant changes in the future. As the remaining Bitcoins become scarcer, profits will gradually decrease, and transaction fees may become the primary source of income. New algorithms may completely change the mining model due to Bitcoin's total supply being capped at 21 million. As the remaining amount available for mining continues to decrease, block rewards will gradually decline until the last Bitcoin is mined around 2140.
According to predictions, within the next decade, the reward for each block may drop below 1 Bitcoin. In this scenario, transaction fees are likely to replace block rewards as the main source of income for miners. As the usage of Bitcoin continues to increase, the fees paid for each transaction will also rise, bringing considerable profits to miners. The Bitcoin community is also actively researching new mining algorithms in hopes of fundamentally changing the existing mining model. For example, the 'RandomX' algorithm under development aims to utilize ordinary CPUs for mining, thereby reducing reliance on specialized mining equipment, achieving true decentralization. Once the new algorithm is widely adopted, traditional large mining farms may lose their advantage, and individual and small miners will regain opportunities to participate. This will fundamentally change the current highly concentrated mining landscape, pushing Bitcoin mining towards a more decentralized direction.
It is noteworthy that, as the amount available for mining gradually decreases, mining difficulty will continue to rise, and the demand for computing power will increase. Therefore, energy consumption and environmental impacts may further intensify, urgently necessitating the search for energy-saving solutions. In this process, the profit model and operation methods of Bitcoin mining may undergo fundamental changes, attracting global attention.
