Updated October 10, 2026. Rewritten as a guide to how difficulty adjustments affect mining income, with the full 2025–2026 history and sources. Earlier versions linked to a live dashboard that is not available.
The April 2024 halving cut the Bitcoin block reward from 6.25 to 3.125 BTC. Since then, two numbers have decided whether a miner makes money: the Bitcoin price and the network’s mining difficulty. This guide explains difficulty in plain terms and walks through what it has done since the halving.
What difficulty is
Bitcoin aims for one new block about every 10 minutes. Every 2,016 blocks (roughly two weeks), the network looks at how fast blocks actually arrived and adjusts the difficulty of the puzzle miners solve. If more computing power (hashrate) joined, blocks came too fast and difficulty goes up. If miners left, difficulty goes down.
For a miner, difficulty sets your share of the pie. The rewards per block are fixed, so when difficulty rises each machine earns less Bitcoin per day, and when it falls each machine earns more.
Hashprice: the number miners actually watch
Hashprice combines difficulty and the Bitcoin price into one figure: dollars earned per unit of hashrate per day, usually quoted per petahash (PH/s). A machine with 235 TH/s is 0.235 PH/s, so at a hashprice of $39 it earns about $9 a day before electricity and fees.
What has happened since the halving
- 2025: Bitcoin rallied to a record of about $126,000 on October 6, 2025, which kept even older machines profitable and pulled in new hashrate. Network hashrate peaked near 1,160 EH/s, and difficulty set an all-time high of 155.97 trillion on October 29, 2025.
- Late 2025 to early 2026: the price fell sharply and big public miners began moving power capacity to AI data centers. In February 2026, difficulty dropped more than 11% after winter-storm curtailments and a price crash. By early March, hashprice hit roughly $28 to $30 per PH/day, the lowest since the halving.
- Spring 2026: difficulty went back and forth. An increase of about 3.9% to roughly 139 trillion on April 3 was followed by three consecutive cuts, including 2.43% on April 17.
- June 2026: difficulty fell 10.09% to 124.93 trillion, about 20% below its peak, as the price slid again.
- Summer to fall 2026: hashrate came back. Difficulty rose to 127.45 trillion by early September, when hashprice had recovered to $39.63, and stood at about 132.7 trillion on October 11, 2026.
The squeeze on older machines
Efficiency is measured in joules per terahash (J/TH), the energy a machine uses for each unit of work. Older S19-series machines use more than 20 J/TH; current models such as the S21+ (16.5 J/TH) and S21 XP (13.5 J/TH) use far less. At post-halving rewards, older machines only make sense on very cheap power, and every machine loses money at typical U.S. home electricity rates. Our buyer’s guide has the full numbers.
Running an Antminer S21+ at a hosted facility in Washington State at 7.4 cents per kWh, I have seen the margin swing between a few dollars a day and close to breakeven as difficulty and price move. That is the practical reality of post-halving mining for a small operator: the economics work at low power prices, but the margin is thin.
Why the adjustment keeps mining viable
The difficulty adjustment is self-correcting. When mining gets unprofitable, some miners shut off, difficulty falls and the survivors earn more. When it gets profitable, new machines plug in and difficulty rises. Mining never stays unprofitable for everyone; the adjustment just decides who can afford to keep going.
That also means a falling difficulty is not a lasting opportunity. 2026 showed how quickly hashrate returns once prices recover. Anyone considering mining should plan around rising difficulty, not the occasional drop.
Sources
- Shattered: Bitcoin hashrate and difficulty in 2026, including the October 29, 2025 record (September 5, 2026)
- CoinMarketCap Academy: BTC mining difficulty drops 10% in second biggest fall of 2026 (June 2026)
- Bex: Q1 2026 miner pivot, hashprice lows and April adjustments (April 22, 2026)
- Bitcoin.com: Difficulty rises, hashprice up 22% (September 6, 2026)
- CoinWarz: Bitcoin difficulty (October 11, 2026)
- Forbes: Bitcoin breaks $125,000 (October 5, 2025)
This content is for informational and educational purposes only and is not financial or investment advice. The author owns a Bitcoin miner and holds BTC.