Bitcoin’s network aims to add a block every ten minutes however many miners join or leave. It does this by changing how hard blocks are to find, roughly every two weeks. This explainer sets out the rule as written in Bitcoin Core’s code and tabulates the 16 most recent adjustments.
Data as of · adjustments through block 973,728 (Oct 29, 2026)
| Date (UTC) | Block height | Difficulty | Change | Direction |
|---|---|---|---|---|
| Oct 29, 2026 | 973,728 | 148.36 T | ▲ +5.54% | Rose |
| Oct 16, 2026 | 971,712 | 140.58 T | ▲ +5.92% | Rose |
| Oct 3, 2026 | 969,696 | 132.72 T | ▼ −0.03% | Fell |
| Sep 19, 2026 | 967,680 | 132.76 T | ▲ +4.16% | Rose |
| Sep 5, 2026 | 965,664 | 127.45 T | ▲ +1.31% | Rose |
| Aug 23, 2026 | 963,648 | 125.81 T | ▼ −1.31% | Fell |
| Aug 8, 2026 | 961,632 | 127.48 T | ▲ +0.99% | Rose |
| Jul 25, 2026 | 959,616 | 126.23 T | ▼ −0.74% | Fell |
| Jul 11, 2026 | 957,600 | 127.17 T | ▼ −5.00% | Fell |
| Jun 27, 2026 | 955,584 | 133.87 T | ▲ +7.15% | Rose |
| Jun 14, 2026 | 953,568 | 124.93 T | ▼ −10.09% | Fell |
| May 29, 2026 | 951,552 | 138.96 T | ▲ +1.72% | Rose |
| May 15, 2026 | 949,536 | 136.61 T | ▲ +3.12% | Rose |
| May 2, 2026 | 947,520 | 132.47 T | ▼ −2.30% | Fell |
| Apr 17, 2026 | 945,504 | 135.59 T | ▼ −2.43% | Fell |
| Apr 3, 2026 | 943,488 | 138.97 T | ▲ +3.87% | Rose |
Date = when the adjustment block (the first block with the new difficulty) was mined, UTC. Difficulty is in trillions (T) as mempool.space reports it. Change = the new difficulty over the previous one, minus 1.3 Observed facts, not a forecast.
Bitcoin’s rules aim for one new block every 10 minutes, set in the code as a target spacing of 600 seconds.2 Mining is the work of finding those blocks, and hashrate is the total computing power doing it. If more hashrate arrives, blocks would come faster than every 10 minutes unless something changes. That something is the difficulty adjustment.
The code changes difficulty only once per “adjustment interval”, which it defines as the two-week target timespan divided by the 10-minute spacing, or 2,016 blocks.2 The check in GetNextWorkRequired is that the next block’s height is an exact multiple of that interval; otherwise the previous difficulty carries over.1 Every block height in the table is a multiple of 2,016 (973,728 is 483 × 2,016).3
The code takes the time between the first and last blocks of the 2,016-block window and scales the old target by that time divided by two weeks.1 Difficulty moves opposite to the target: a larger target means lower difficulty. If the window took longer than two weeks, the target grows and difficulty falls; if it took less, the target shrinks and difficulty rises.1
Of the last 16 adjustments, 9 raised difficulty and 7 lowered it. The largest rise was June 27, 2026 (+7.15%) and the largest fall June 14, 2026 (-10.09%). The latest, at block 973,728 on October 29, 2026, set difficulty at 148.36 trillion.3
A change in difficulty records how long the previous 2,016 blocks took; it is set after the fact and does not measure hashrate on any given day. For related rankings, see the biggest difficulty increases, the biggest drops and hashrate growth by year. The table describes what happened and says nothing about what comes next.
GetNextWorkRequired and CalculateNextWorkRequired), master branch, retrieved 2026-11-09.nPowTargetTimespan = 14 days and nPowTargetSpacing = 10 minutes, and src/consensus/params.h: DifficultyAdjustmentInterval() = timespan ÷ spacing; retrieved 2026-11-09.For information only. Not financial advice. See the terms of use.