How Bitcoin network difficulty affects mining and cryptocurrency emission
What is Bitcoin network difficulty?
The Bitcoin Network Difficulty is a metric that indicates the amount of computational power required by miners to find and add one block to the blockchain. It is also referred to as "Bitcoin mining difficulty" or "Bitcoin extraction difficulty."
Network difficulty is measured in hashes per second. However, since the computational power (hash rate) of the network is also calculated in the same units, only multipliers are used to represent difficulty: kilo (K), mega (M), giga (G), tera (T), and so on.
Mining difficulty is a characteristic of blockchain networks based on the Proof-of-Work (PoW) consensus mechanism, such as Bitcoin, Litecoin, Dogecoin, and Ethereum (before the 2022 The Merge update). Decentralized networks of the next generation, based on other popular consensus mechanisms such as Proof-of-Stake (PoS) and its variations, do not have this metric.
Network difficulty is designed to increase as the overall computational power of miners grows and decreases when it falls. Bitcoin's difficulty stabilizes the emission of cryptocurrency, ensuring that the average time to mine a new block remains approximately 10 minutes.
According to the algorithm, Bitcoin's mining difficulty is recalculated regularly to maintain the emission rate of the first cryptocurrency at the same level throughout each halving cycle*.
If the Bitcoin network's hash rate increases, miners spend less time searching for and adding a new block to the blockchain, which accelerates the emission rate of the cryptocurrency.
On the other hand, if the hash rate decreases, Bitcoin becomes harder to mine, and its emission rate slows down. This also means that miner profitability decreases, which depends on the ratio of electricity costs and Bitcoin's value.
To prevent this from happening, the Bitcoin mining difficulty is recalculated by the algorithm every 2,016 blocks or approximately every two weeks. If the actual time taken to mine a new block differs from the standard time, the difficulty is adjusted accordingly. Through this mechanism, the emission of cryptocurrency becomes controlled and predictable. In other words, difficulty and hash rate are closely linked, which helps maintain Bitcoin's deflationary mechanism.
* Halving is a deflationary mechanism that reduces miner rewards and the rate of cryptocurrency emission by half at specific intervals.
Current Bitcoin network difficulty and its changes
According to the BitInfoCharts service for June 2025, the current difficulty of the Bitcoin network has exceeded a record 126 T. Since the beginning of 2025, this figure has increased by 14.5%, and over the past five years, it has risen by more than nine times. This indicates significant growth in the mining industry and a corresponding increase in overall interest in Bitcoin.
Back in early 2017, the Bitcoin network difficulty did not exceed 500 G — approximately 250 times less than the current level. Initially, regular computer processors (CPUs) were used for Bitcoin mining. Their power was sufficient for mining Bitcoin, as the network's difficulty was less than 1 K until 2010.
However, as the difficulty of mining Bitcoin and the number of miners grew, the power of processors became insufficient. By 2013, ASIC devices specifically designed for Bitcoin mining had been developed, which were significantly more potent than CPUs. These devices led to a significant increase in the Bitcoin network's hash rate and difficulty.
The power of the first ASIC miner was 1 TH/s — thousands of times greater than even modern processors, whose performance exceeds just 100 KH/s (kilohashes per second).