Bitcoin mining is the process for validating Bitcoin transactions and minting new coins. Since Bitcoin is decentralized, there’s no central authority managing transactions or issuing coins like there is with government-backed currencies. Bitcoin miners, who can be anyone, handle this instead.
To record transactions, Bitcoin uses a blockchain, a public ledger that contains all of Bitcoin’s transactions. Miners check each block, and, once they confirm it, they add it to the blockchain.
For helping to keep the network secure, miners earn Bitcoin rewards as they add blocks. The rewards are paid using transaction fees and through the creation of new Bitcoin. However, there is a fixed maximum supply of 21 million Bitcoins. Once that many are in circulation, rewards will be paid entirely using transaction fees.
How Bitcoin mining works
The Bitcoin mining process always starts with a block that contains a group of transactions. The transactions have already gone through an initial security check by the network to verify that the sender has enough Bitcoin and has provided the correct key to their wallet.
Here’s what occurs next to mine a block:
- The network creates a hash (a string of characters) for the block of transactions. Bitcoin uses an algorithm called SHA-256 to do this, and it always generates hashes with 64 characters.
- Bitcoin miners start generating hashes using mining software. The goal is to generate the target hash — one that’s below or equal to the block’s hash.
- The first miner to generate the target hash gets to attach the block to their copy of the Bitcoin blockchain.
- Other miners and Bitcoin security nodes check that the block is correct. If so, the block is added to the official Bitcoin blockchain.
- The Bitcoin miner then receives block rewards. Blocks offer a set amount of Bitcoin as a reward; the amount is cut in half for every 210,000 blocks that are mined (this is called Bitcoin halving).
- This system Bitcoin uses is called proof of work because miners need to prove they expended computing power during the mining process. They do this when they provide the target hash.
One important thing to know about Bitcoin mining is that the network varies the difficulty to maintain an output of one block every 10 minutes. When more miners join, or they start using mining devices with more processing power, mining difficulty increases.
Types of cryptocurrency mining
There are several types of cryptocurrency mining depending on the method you choose. Here are the most popular ways to mine Bitcoin.
An application-specific integrated circuit (ASIC) is a specialized device built for one purpose, and ASIC miners are designed for mining a specific cryptocurrency. These are the most powerful option for Bitcoin mining. New ASICs can cost thousands of dollars, but they’re also the only type of device where you can potentially make a profit from Bitcoin mining.
GPU mining uses one or more graphics cards to mine crypto. A typical “mining rig” is a computer that has one or more high-end graphics cards. This kind of mining is costly up front because you need to buy the graphics cards. Although it’s popular for mining other types of cryptocurrency, it doesn’t work well for Bitcoin due to the lack of power compared to ASICs.
CPU mining uses a computer’s central processing unit. This is the most accessible way to mine crypto since all you need is a computer, and it worked in the early days of Bitcoin. It’s no longer recommended for mining Bitcoin because CPUs don’t have nearly enough processing power to compete with ASICs.
Cloud mining involves paying a company to mine crypto for you. Instead of setting up your own mining device, you’re essentially renting one and receiving the profits after maintenance and electricity costs are deducted. While it may sound like a good deal at a glance, cloud mining normally requires committing to a contract, and, if crypto prices fall, you’re unlikely to break even.
A mining pool is a group of crypto miners who pool their resources and share rewards. By working together, miners are much more likely to get the chance to mine new blocks. With Bitcoin mining, it’s very difficult to mine blocks if you’re operating solo. Each mining pool has its own hardware requirements, with most requiring you to have either an ASIC miner or a GPU.
Is Bitcoin mining profitable?
Bitcoin mining usually isn’t profitable for individuals anymore because of the costs involved and the competition.
Here are the main factors that determine how much you can make mining Bitcoin:
- Cost of the mining device: Quality ASICs range from about $1,000 to more than $15,000.
- Hash rate: The hashes per second the mining device can generate. The higher this is, the more you earn. This is expressed as terahashes per second (TH/s), or how many trillions of hashes the device generates per second.
- Efficiency: The amount of energy a mining device requires. This is expressed as watts per terahash (W/TH), or the number of watts the device needs to generate a trillion hashes.
- Electricity costs: The price you pay for electricity. The only way to make money mining Bitcoin is with cheap electricity.
- Price of Bitcoin: Bitcoin is extremely volatile, and the amount you earn will rise or fall with its price movements.
Fortunately, you don’t need to do the math yourself. There are plenty of mining profitability calculators available. Plug in how much you pay for electricity, and the calculator will tell you how much passive income you could expect to earn per day, per month, and per year.
Divide the earnings by the cost of the mining device to find out how long it will take before you’re turning a profit. In most cases, it’s more than a year and often more than two. Keep in mind that it could end up taking even longer because of mining difficulty increases.
The other problem is that mining devices have a limited lifespan. With proper maintenance and care, three to five years is about average, but they’re often obsolete by the three-year mark.
To sum it up, Bitcoin mining offers very limited profitability at best and requires a big initial financial commitment.