By Saurav Cryptocurrency mining works by having powerful computers compete to solve a mathematical puzzle, and the first to succeed earns the right to add the next block of transactions to the blockchain and collect a reward in newly created coins plus transaction fees. The puzzle can’t be shortcut: the only way to solve it is to make an enormous number of guesses, which costs real electricity and equipment, and that cost is precisely what makes the network hard to cheat. This process, called proof of work, secures Bitcoin and a handful of other cryptocurrencies, while many newer networks (including Ethereum since September 2022) have moved to a different system called proof of stake and no longer use mining. Here’s how mining works step by step, what it takes to do it today, and why most individuals now join pools instead of mining alone. This is general information, not investment advice.
What Miners Actually Do
Miners do three jobs at once:
- They process transactions, collecting pending payments from the network’s waiting area (the mempool) and bundling them into a block.
- They secure the ledger, because rewriting history would require redoing the work of every block that followed.
- They issue new coins, since the block reward is how new bitcoin enters circulation, up to the 21 million cap.
The Mining Process, Step by Step
Step 1: Collect transactions. A miner picks pending transactions, typically favouring those paying higher fees, and checks that each one is valid.
Step 2: Build a candidate block. The miner assembles them into a block, adds a special first transaction paying the block reward to their own address, and includes a reference to the previous block, which links the chain together.
Step 3: Hash the block header. A hash function (SHA-256 for Bitcoin) turns the block header into a fixed-length string of characters. Change even a tiny detail and the output changes completely and unpredictably.
Step 4: Search for a winning number. The header contains a field called a nonce. The network sets a target, and a block is valid only if its hash is below that target (in practice, it must start with a certain number of zeros). The miner changes the nonce and rehashes over and over, trillions of times per second, until a hash meets the target.
Step 5: Broadcast the block. The first miner to find a valid hash announces it to the network.
Step 6: Everyone verifies. Other computers check the block in an instant, since verifying a solution is easy even though finding one is hard.
Step 7: The chain grows. If the block is valid, nodes add it, miners start working on the next one, and the winner receives the reward.
Why It’s Hard to Cheat
- Cost makes dishonesty expensive. To alter a past transaction, an attacker would have to redo the work for that block and every block after it, faster than the rest of the network combined.
- More hashing power means more security. Bitcoin’s network was running at roughly 900 to 1,000 exahashes per second in 2026, close to a zettahash (a 1 followed by 21 zeros of guesses every second).
- The difficulty adjusts itself. Bitcoin’s target changes every 2,016 blocks, about every two weeks, so blocks keep arriving roughly every 10 minutes whether the network has little or enormous computing power. If miners join and blocks come faster, difficulty rises, and if they leave, it falls.
What Miners Earn
- The block reward:125 BTC per block since the halving in April 2024, which falls to 1.5625 BTC at the next halving, expected around April 2028.
- Transaction fees: paid by users and collected by the winning miner. These matter more as the reward shrinks.
Each halving cuts the reward in half, which is how Bitcoin’s supply schedule heads toward its 21 million limit.
The Hardware
- ASICs (application-specific integrated circuits) are machines built to do one thing: compute SHA-256 hashes extremely fast and efficiently. They dominate Bitcoin mining, and the best current models run at roughly 15 to 20 joules per terahash, with older, less efficient machines pushed out as margins tighten.
- GPUs (graphics cards) were once popular for mining other coins, but many of those networks have since moved away from proof of work, and GPU mining is now a niche activity.
- Supporting equipment includes power supplies, cooling, and fast internet.
Efficiency, measured in joules per terahash, is the most important specification, because electricity is the largest ongoing cost.
Why Most People Mine in Pools
Finding a block alone is a lottery with very long odds.
- A simple illustration: a single modern machine producing 100 terahashes per second against a network of about 1,000 exahashes per second has a share of roughly one in ten million. With about 144 blocks mined a day, that machine would be expected to find a block about once every 190 years.
- Pools combine many miners’ power and split the rewards in proportion to the work each contributes, giving a steadier, predictable income.
- Pools charge fees, typically around 1% to 3% of revenue.
- Pool concentration is a topic of discussion, as a small number of large pools produce a big share of blocks, though miners can switch pools at any time.
The Economics: Revenue Versus Electricity
Miners are paid in bitcoin but pay their bills in local currency, so profitability depends on several moving parts.
- Bitcoin’s price, which sets the value of the reward.
- Network difficulty, which sets how much of the reward your hashing power earns.
- Electricity price, the biggest cost.
- Hardware efficiency and cost, including depreciation as better machines arrive.
- Pool fees, cooling, and hosting.
- The halving, which cuts the reward every four years.
A common industry measure is hashprice, the revenue earned per petahash per second per day. In 2026 it has ranged roughly between the mid-30s.
A rough illustration, with assumed numbers: take a 100 TH/s machine, which is 0.1 PH/s, at a hashprice of $30 per PH/s per day. Gross revenue is about $3 per day. If the machine uses about 17 joules per terahash, it draws roughly 1,700 watts, or about 41 kWh a day.
- At $0.07 per kWh, electricity costs about $2.86 a day, leaving a margin of only a few cents before pool fees and other costs.
- At $0.10 per kWh, electricity costs about $4.08 a day, which exceeds revenue.
This shows why cheap power, efficient hardware, and scale matter, and why many small operators find it difficult to turn a profit at home. Break-even points shift with the price of bitcoin and network difficulty, so check current figures.
Energy and the Environment
- Mining uses a lot of electricity, by design, since the cost of computation is what secures the network.
- The energy mix varies. Many miners seek the cheapest power, which can include hydroelectric, wind, solar, flared natural gas, or otherwise unused or curtailed energy, as well as grid power that includes fossil fuels.
- Some miners can help balance grids by switching off during demand peaks, as when Texas operators curtailed during a winter storm in early 2026.
- Heat reuse and efficiency gains are active areas of development.
- Debate continues about the environmental impact, and many networks have chosen proof of stake in part to use far less energy.
Mining Versus Staking
- Proof of work (mining) secures the network with computing power and electricity, as in Bitcoin and Litecoin.
- Proof of stake secures the network with coins that validators lock up as collateral, as in Ethereum today.
- Different trade-offs: proof of work ties security to physical resources, while proof of stake ties it to economic stakes and uses far less energy.
Cloud Mining and Other Cautions
- Cloud mining, where you pay a company to mine on your behalf, carries significant counterparty risk, and many offers have turned out to be unprofitable or fraudulent.
- Unrealistic promises of guaranteed daily returns are a red flag.
- Hardware can lose value quickly as newer, more efficient machines arrive.
- Noise and heat make home mining impractical for many.
India-Specific Notes
- Mining is not banned in India, but crypto income is taxed heavily, with a flat rate on gains and generally no deduction for electricity or hardware costs, so check the latest provisions.
- Electricity costs and rules apply, and unauthorised use of power is illegal.
- Selling mined coins requires using a registered exchange, with a 1% TDS on eligible transactions.
- Rules continue to evolve, so stay informed and keep careful records.
Frequently Asked Questions
Q1. Can I mine Bitcoin on my laptop or phone?
A. Not in any meaningful way. Modern Bitcoin mining relies on specialised ASIC hardware, and ordinary laptops or smartphones cannot compete efficiently with dedicated mining equipment.
Q2. What is a nonce in Bitcoin mining?
A. A nonce is a number miners repeatedly change in the block header to generate different hashes. Miners continue trying different values until they find a hash that satisfies the Bitcoin network’s current difficulty target.
Q3. Why does Bitcoin mining difficulty change?
A. Bitcoin’s mining difficulty adjusts every 2,016 blocks to keep the average time between blocks close to 10 minutes. Difficulty generally increases when more computing power joins the network and decreases when computing power falls.
Q4. Is Bitcoin mining still profitable?
A. Profitability depends on several factors, including electricity costs, ASIC efficiency, Bitcoin’s market price, network difficulty, and mining rewards. Mining margins have become more challenging for many operators since the 2024 Bitcoin halving reduced the block subsidy.
Q5. Does Ethereum still use mining?
A. No. Ethereum switched from Proof of Work (PoW) to Proof of Stake (PoS) in September 2022 through an upgrade known as The Merge. As a result, Ethereum is no longer mined using traditional cryptocurrency mining hardware.