While Bitcoin mining has made a decent enough profit for a lot of people, this will not last forever due to the design of the mining process. In fact, Bitcoin itself is created to have a maximum supply of only 21M BTC. Along the way, it cuts the mining rewards in half each time when it reached 210,000 new blocks.
Eventually, all of the BTC coins will be mined, and mining will simply no longer be possible. With that in mind, we will now try to calculate for how long will mining BTC be possible according to its past, present, and potential future.
BTC Mining Will Have To Have An End
When Bitcoin mining first started, the mining rewards per block were 50 coins. This lasted for three years until BTC reached its 210,000th block on November 28, 2012. This is the date when the reward for ‘solving' each block was cut in half, and instead of 50 BTC, the miners would only receive 25 BTC for each block.
In dollars, the value of reward went from $1,250 to $625. This is also when the price of BTC started to see significant increases. Then, on July 9, 2016, it happened again. Bitcoin once again reached its 210,000th block, and the reward dropped from 25 BTC to 12.5 BTC. Only, this time, the dollar value was much bigger, and the reward went down from $16,500 to $8,250.
This is the last time that Bitcoin mining rewards were cut in half, at least to this day. However, Bitcoin's price continued to rise so much, that the miners were able to make a profit even with the two rewards halvings behind them. Currently, the reward per block is worth $84,000, which is more than a tenfold increase from two years ago, when the halving occurred, and the reward was $8,250.
So, When Will The Next Halving Happen?
As of August 26, 2018, BTC has reached its 538,658th block, which is slightly more than halfway on its road to the next halving, which is scheduled to happen once it reaches the 630,000th block. When it happens, the mining reward will be only 6.25 BTC per each individual block.
At the current pace, analysts predict that this should happen in April/May of 2020, which is as precise as the calculations can get at this moment. The mining of an average BTC block is at around 10 minutes, but even this is subjected to change, especially since the hash rate is rising as the time passes. Additionally, the block difficulty is updated after every two weeks or 2,016 blocks.
It should also be mentioned that around 82% of all Bitcoin that will ever exist is already mined, and in circulation right now. This is around 17,233 coins, which leaves us with only 3.77 million of unmined coins, waiting to be ‘dug up'. Obviously, the days of making a profit by mining BTC are coming to an end, and will eventually dry up completely.
However, Bitcoin still continues to rise, and if the trend continues, it might yet make its miners millionaires when the blockchain dries up completely.
The fourth block halving is expected to come after the 840,000th block has been mined, which is expected to be in 2024. Additional block halvings are to come in 2028, 2032, 2036, 2040, and so on, until unmined Bitcoin falls to its smallest unit — 1 Satoshi.
After that, block rewards will drop to 0, and miners will only continue to receive transaction fees for their hard work. This is expected to occur when Bitcoin blockchain gets to its 33rd halving, which will not happen for over 130 years after the first block.