Michal Beno4 November 2026 · Hashing 101
1The one-sentence version
Bitcoin mining is a giant guessing game. Every Bitcoin miner on Earth is trying to find a number that, when mixed with the next block of transactions, produces a result below a certain line. The first to find it adds the block to the chain and collects the reward: 3.125 BTC of new Bitcoin plus the transaction fees inside the block.
That is it. The rest of this guide explains the four words that make the game work: hash, nonce, target and difficulty. No maths degree needed.
2Step 1: the hash, a digital fingerprint
A hash function takes any input and turns it into a fixed-length string that looks random. Bitcoin uses one called SHA-256. Three facts about it matter:
- Same input, same output, every time.
- Change one character of the input and the output changes completely.
- There is no shortcut. The only way to find an input with a certain kind of output is to try inputs one by one.
That last point is the whole idea of proof of work. A low hash is proof that someone did a huge number of tries, because there is no other way to get one. For more background, read proof of work explained.
3Step 2: the block header and the nonce
A miner does not hash the whole block. It hashes a short summary called the block header. The header holds a few fields: a link to the previous block, a fingerprint of all the transactions in the new block, a timestamp, the current target, and one free field called the nonce. Nonce means 'number used once'.
Everything in the header is fixed except the nonce. So the miner changes the nonce, hashes the header, checks the result, changes the nonce again, and repeats. Each try is one hash.
| Possible nonce values | 4,294,967,296 (about 4.3 billion) |
| S21 hashrate | 188 TH/s = 188 trillion hashes per second |
| Time to try every nonce (4.3 billion / 188 trillion) | about 22.8 millionths of a second |
| Hashes per day (188 trillion x 86,400) | about 16.2 quintillion |
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In the catalogue Antminer S21
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4Step 3: the target, or the dice game
Picture a dice game. A referee says: 'Roll a number below 5 on a 100-sided die and you win.' Every roll has a 4 in 100 chance. Nothing you did before changes the next roll. Rolling faster is the only way to win more often.
Bitcoin works the same way. The die is SHA-256, each roll is a hash, and the 'below 5' line is the target. A winning hash must be smaller than the target. In practice the winning hash, written in hexadecimal, starts with about 19 zeros. Almost every hash misses.
5Step 4: difficulty keeps the clock at 10 minutes
If more miners join, rolls per second go up and blocks would come faster. To stop that, Bitcoin resets the target every 2,016 blocks, which is about two weeks. If blocks arrived too fast, the target gets smaller and difficulty rises. If too slow, the target grows and difficulty falls. The aim is always one block every 10 minutes on average.
| Target time for 2,016 blocks | 14 days |
| Difficulty change (public data, 30 Oct 2026) | +5.5% |
| Actual time implied (14 / 1.055) | about 13.27 days |
| Average block time implied (10 / 1.055) | about 9.48 minutes |
6What are the odds for one Bitcoin miner?
Here the numbers get fun. With the network at about 1,000 EH/s, which is 1,000,000,000 TH/s, the whole planet makes roughly 600 sextillion hashes for every block found. A single miner's chance of winning the next block is simply its share of all the guessing.
With 144 blocks per day, the S21's expected wait to find a block alone is about 36,900 days. That is roughly 101 years. Bigger miners shorten the wait, but not by enough.
| 135 years |
| 101 years |
| 33.8 years |
| 18.2 years |
7Why miners join pools
No one wants to wait a century for a prize. So miners join a mining pool, which combines thousands of miners into one huge roller. The pool finds blocks often and splits the reward by how much work each member did. Each member proves its work by sending 'shares': hashes that beat an easier, pool-set target. Shares cannot win a block on their own, but they show the pool how hard each miner is rolling.
Instead of a 1 in 5.3 million shot per block, an S21 owner gets a small, steady slice every day. Using about 3.5 cents per TH per day as a hashprice estimate, that is about $6.63 a day for 188 TH/s. More on that trade-off in solo mining vs mining pools.
| 1,048 TH/s |
| 563 TH/s |
| 255 TH/s |
| 188 TH/s |
| 141 TH/s |
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In the catalogue Whatsminer M79S
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8Common myths about hashing
See all sites on the hosting page and test any miner in the profitability calculator. For the unit behind all of this, read hashrate explained.
9Frequently asked questions
This article is for education only and is not financial advice. Mining revenue depends on the Bitcoin price, network difficulty, fees, power costs and uptime, all of which change. Figures are estimates based on public network data and rates listed on oneminers.com on 30 October 2026; check the live pages for current rates and prices.
