How Long Does It Take to Mine One Bitcoin

How Bitcoin Mining Works

Bitcoin is mined in blocks, rather than in a consistent stream. Roughly every ten minutes, a block is produced by a miner, earning that miner new bitcoin. Mining is a random—or stochastic—process, more akin to a lottery than a construction project in the sense that past work does not bring a miner any closer to mining a block.

The amount of bitcoin earned by a miner for a single block can vary. Currently, every block produces 6.25 new bitcoin, called the block subsidy. This subsidy will halve every four years as determined in the Bitcoin software that the network agrees to run. In addition, miners collect fees from every transaction included in their block. Today, fee revenue is volatile, and it forms a small portion of the total block reward.

Mining’s random nature, the halving, and the variance in transaction fees make revenue from Bitcoin mining unpredictable for smaller miners over a short period; blocks are difficult to find but extremely lucrative.

How Long Does It Take to Mine One Bitcoin?

For an individual mining with just one ASIC or computer, mining a full bitcoin would take many years. There is less than 7% of all the bitcoin supply left to be mined, and competition over it is fierce.

There are several factors that determine the revenue of a Bitcoin mining operation and the time it will take to mine a single bitcoin. These factors can provide meaningful estimates for the revenue of a mining operation in bitcoin terms, but given the volatility of bitcoin price, energy prices, and Bitcoin’s difficulty, all calculations are dynamic and probabilistic.

Hash Rate

The most important factor in determining a mining operation’s revenue in a given time frame is the amount of hash rate dedicated to the operation. The best way to win a lottery is to buy as many tickets as possible; the same is true for bitcoin mining.

Special computers called ASICs are built solely to mine bitcoin with extreme efficiency and speed. The more ASICs a miner can deploy, the more lottery tickets they will accumulate, and the higher the chance that they will eventually create a block. To take this race to the next level, most miners organize themselves in mining pools. A pool helps them earn smaller amounts consistently, rather than waiting for a long time for a larger reward.

➤ Learn more about how Bitcoin mining pools work.

Bitcoin’s Difficulty Adjustment

The Bitcoin network has a mechanism for ensuring that no matter how much hash rate is produced by all miners, one new block is only created on average every ten minutes. This mechanism is called the difficulty adjustment.

➤ Learn more about Bitcoin’s difficulty adjustment.

The difficulty adjustment renders absolute hash rate less significant to an operation’s revenue than the miner’s share of hash rate relative to the entire network. If a mining operation has 10% of the network hash rate, they will mine an average of 10% of all blocks. Since blocks are produced at a constant, if probabilistic, rate, it is possible to calculate the operation’s expected revenue over a period of time.

Bitcoin’s Price

The calculation above determines the revenue of a given mining operation in bitcoin terms. However, most miners pay their costs—salaries, rent, and energy costs—in fiat currencies such as the U.S. dollar or the Chinese Yuan. Therefore, the price of bitcoin matters a great deal to miners.

When the price of bitcoin drops, some miners no longer find it profitable to mine. When they stop producing hash rate, the difficulty decreases, and remaining miners have an easier time finding blocks because they comprise a greater portion of the total hash rate.

Conversely, when the price rises, more miners join the network, driving the difficulty up. Every existing miner will see their share of total hash rate decline, leading to a decline in their expected revenue as denominated in bitcoin. However, since the price of bitcoin is rising, their revenue denominated in fiat could still rise.

Bitcoin Mining Profitability

The above calculations estimated Bitcoin mining revenue. However, Bitcoin mining involves heavy costs, often yielding thin profit margins.

-- Satoshi Nakamoto explaining how the cost of mining will mirror the price of Bitcoin

Due to Bitcoin’s difficulty adjustment, the marginal cost of mining one bitcoin will forever approach the value of one bitcoin. This means that, if the price of bitcoin is at $50,000, the price of mining one bitcoin will tend towards $50,000. For many individuals, the costs will greatly exceed $50,000, making it unprofitable to mine.

➤ Learn more about Bitcoin mining profitability.