Bitcoin Difficulty Tracker
Live Bitcoin mining difficulty and the countdown to the next retarget.
Current Bitcoin network difficulty: 126.23 T
Next difficulty retarget in
- Blocks to retarget
- 1,684
- Previous adjustment
- -0.74%
- Projected next change
- -3.86%
- Current block height
- 959,948
Current Bitcoin mining difficulty is 126.23 T. The next retarget is projected in approximately 12 days.
Network and block data from mempool.space.
Learn about our methodology →
Methodology
We verify every formula against primary sources, run it on live data, and document each model's assumptions and limits.
Learn about our methodology →
Built and reviewed by Fabio Arcieri
Fabio Arcieri
Founder, Orange Abacus
Bitcoin researcher with a background in economics and a decade in digital marketing. He builds and reviews every calculator on this site against primary sources.
Read full profile →Last reviewed: July 2026
Key difficulty adjustment terms
Bitcoin’s difficulty adjustment relies on a small set of protocol-level terms with precise technical meanings.
| Term | Meaning |
|---|---|
| Difficulty | A dimensionless number representing how hard it is to find a valid block hash below the network’s current target. Higher difficulty means more attempts are needed on average. |
| Hash rate | The total computing power the network dedicates to mining, measured in hashes per second. Difficulty is derived from hash rate at each retarget. |
| Target | The numeric threshold a block’s hash must fall below to be valid. A lower target means fewer qualifying hashes exist, which is mathematically equivalent to higher difficulty. |
| Difficulty epoch | The 2,016-block period between retargets, lasting about 2 weeks at the 10-minute block target. |
| Retarget | The recalculation that occurs every 2,016 blocks, adjusting difficulty up or down based on how long the previous epoch actually took. |
| Block time | The interval between consecutive blocks. Bitcoin’s protocol targets an average of 10 minutes (600 seconds) per block. |
Metrics of the Bitcoin difficulty
Difficulty is a plain, unitless number. The suffixes on the tracker and chart are standard metric prefixes, each 1,000 times the one before.
| Suffix | Name | Value |
|---|---|---|
| K | kilo | thousand (10³) |
| M | mega | million (10⁶) |
| G | giga | billion (10⁹) |
| T | tera | trillion (10¹²) |
| P | peta | quadrillion (10¹⁵) |
| E | exa | quintillion (10¹⁸) |
How the difficulty retarget works
Bitcoin recalculates mining difficulty on a fixed schedule, entirely from the network’s own block timestamps. That recalculation, the retarget, works from three things:
- A 2,016-block epoch: difficulty stays fixed for exactly 2,016 blocks, then the protocol recalculates it. That span is one difficulty epoch.
- A 2-week target: at the 10-minute block target, 2,016 blocks should take 20,160 minutes, almost exactly 2 weeks. Actual pace is measured against that target.
- A proportional adjustment: the formula scales difficulty by how far the epoch ran from the target. An epoch that finished faster than 2 weeks raises difficulty, a slower one lowers it, with the change capped at 4x in either direction per retarget.
The tracker above works as a live Bitcoin difficulty estimator, showing the current difficulty, how far the epoch has progressed, and the projected change as each new block is mined. That projection stays an estimate until the epoch’s final block confirms and the retarget locks in the new difficulty.
Why Bitcoin difficulty adjusts
Bitcoin’s protocol targets a 10-minute average block time regardless of how much hash power is competing to mine. Without a correction, a sudden influx of hash power would shorten block times and accelerate issuance beyond the fixed schedule. An exodus would do the opposite, stretching block times and slowing the network down.
The retarget every 2,016 blocks is the self-correcting mechanism that prevents both outcomes. If the previous epoch finished faster than 2 weeks, difficulty rises by the same proportion the network ran ahead of schedule. If the epoch ran slower than 2 weeks, difficulty falls by the equivalent margin. The adjustment reads the network’s own block timestamps and executes automatically, with no operator, vote, or external input required.
Bitcoin difficulty vs. hash rate
Difficulty and hash rate move together, but hash rate leads and difficulty follows. Total hash power can shift block by block as miners power hardware on or off, while difficulty only updates at each retarget. That gap means difficulty always reflects hash rate as it stood over the epoch that just closed.
When new hash power joins the network, blocks get found faster than the 10-minute target for the rest of that epoch. The next retarget then raises difficulty to match, pulling the average block time back toward 10 minutes. When hash power leaves, the opposite happens: blocks slow down during the epoch, and the next retarget lowers difficulty to compensate.
The relationship is mechanical, not discretionary. Difficulty is always a lagging, calculated response to hash power, never an independent input.
Bitcoin difficulty over time
The difficulty chart above, also read as a graph, plots every retarget over the last 3 years, tracing the network’s long-term trend against the epoch-to-epoch noise of individual adjustments.
Across that window, difficulty has trended upward across nearly every epoch, interrupted only by brief negative retargets when a cluster of miners drops offline at once. The steepest single-epoch decline in Bitcoin’s history came on July 3, 2021, when difficulty fell by around 28%. The drop followed China’s ban on domestic mining, which forced a majority of global hash power offline within weeks.
Most negative adjustments visible in the chart are far smaller, typically a few percent, and the network has historically recovered its upward trajectory within several epochs of any drop. The long-run direction reflects sustained investment in mining hardware and energy access rather than any single event.
Frequently asked questions
How often does Bitcoin difficulty adjust?
Bitcoin difficulty retargets every 2,016 blocks, roughly every 2 weeks. The protocol compares how long those 2,016 blocks actually took against the 2-week target and adjusts the difficulty up or down to steer the average block interval back toward 10 minutes.What is Bitcoin mining difficulty?
Mining difficulty is a measure of how hard it is to find a valid block hash below the network's target. It rises when more hash power joins the network and falls when hash power leaves, keeping blocks spaced about 10 minutes apart regardless of how much mining power is online.How is Bitcoin difficulty calculated?
Bitcoin difficulty is calculated by comparing the actual time the last 2,016 blocks took to mine against the 20,160-minute (2-week) target, then scaling the difficulty by that ratio. If the epoch finished faster than 2 weeks, difficulty rises by the same proportion; if it finished slower, difficulty falls. The formula also caps the adjustment at a maximum factor of 4 up or down per retarget, a safeguard against extreme single-epoch swings. The result becomes the new target threshold a valid block hash must fall below for the next 2,016 blocks.Does higher Bitcoin difficulty mean a more secure network?
Higher Bitcoin difficulty generally means a more secure network. It reflects more hash power competing to produce blocks, which raises the cost of gaining enough hash power to rewrite the blockchain. Difficulty tracks hash power with a lag of up to 2 weeks, so a short-term dip does not necessarily signal reduced security if hash power is already recovering. Security depends on sustained hash power, not on the difficulty figure at any single moment.Can Bitcoin difficulty go down?
Bitcoin difficulty can go down, and does whenever the network's hash power falls between retargets. A drop happens when miners go offline, typically due to rising energy costs, regulatory action, or older hardware becoming unprofitable. The protocol has recorded numerous negative adjustments across Bitcoin's history, though a 4x maximum adjustment factor caps any single retarget's drop at 75%. A lower difficulty makes it proportionally easier for the remaining miners to find valid blocks, holding the 10-minute target steady.What was the largest Bitcoin difficulty drop in history?
The largest Bitcoin difficulty drop in history occurred on July 3, 2021, when difficulty fell by around 28% in a single retarget. The drop followed China's ban on domestic Bitcoin mining, which forced an estimated majority of global hash power offline within weeks. The adjustment remains the steepest single-epoch decline the network has recorded, well beyond typical multi-percent swings between retargets.