Every 210,000 blocks, roughly every four years, the bitcoin a miner earns for finding a block is cut in half. Nothing else about the machine changes. It draws the same power, produces the same hashrate and needs the same maintenance, but overnight it earns about half as much bitcoin.
For an operator, the halving is the single most predictable shock in the business. Here is how it works, what it does to fleet economics, and how to prepare for the next one.
The halving so far
| Halving | Approximate date | Block reward |
|---|---|---|
| Launch | January 2009 | 50 BTC |
| First | November 2012 | 50 → 25 BTC |
| Second | July 2016 | 25 → 12.5 BTC |
| Third | May 2020 | 12.5 → 6.25 BTC |
| Fourth | April 2024 | 6.25 → 3.125 BTC |
| Fifth | Expected around April 2028 | 3.125 → 1.5625 BTC |
The date is set by block height, not the calendar, so it drifts by a few weeks depending on how fast blocks are found. The amount is never in doubt.
What changes for your machines
Miner revenue comes from two sources: the block reward and transaction fees. For most of the network’s history the reward has been by far the larger part. When it halves, revenue per terahash falls by close to half unless bitcoin’s price, transaction fees or a drop in network difficulty make up the gap.
The cost side does not move at all. Power, hosting, labour and repairs cost the same the day after the halving as the day before. That is why the halving hits older, less efficient machines hardest: their power bill takes a bigger share of revenue to begin with.
A simple way to see it is through hashprice, the revenue one unit of hashrate earns per day (see What Is Hashprice?). If bitcoin’s price and network hashrate stayed where they are, a hashprice of about $40/PH/day would fall to about $20/PH/day after the next halving. Here is what that does to the power-cost margin of some common efficiency levels at $0.05/kWh:
| Efficiency | Power cost per PH/day | Margin at $40/PH/day | Margin at $20/PH/day |
|---|---|---|---|
| 34 J/TH | $40.80 | −$0.80 | −$20.80 |
| 21.5 J/TH | $25.80 | $14.20 | −$5.80 |
| 17.5 J/TH | $21.00 | $19.00 | −$1.00 |
| 13.5 J/TH | $16.20 | $23.80 | $3.80 |
Power cost per PH/day = J/TH × 24 × $/kWh. Margin covers power only, before hosting, labour and repairs.
In practice price and difficulty never sit still. Some machines switch off, difficulty adjusts down, and the survivors earn a little more. But the table shows the starting point: a halving can turn a comfortably profitable machine into a marginal one overnight. The same logic doubles every value in our shutdown price table.
What usually happens around a halving
- Older machines drop off. Units near their shutdown price are switched off, moved to cheaper power, or sold to regions with lower costs.
- Difficulty eases, then recovers. As hashrate leaves the network, difficulty falls at the next adjustments, which gives the remaining machines some relief until new capacity arrives.
- Older machines lose resale value. A model expected to be unprofitable after the halving is worth less to a buyer, because it has fewer profitable months left.
- Efficiency becomes the whole story. J/TH and power price decide which fleets keep running. Uptime matters more because there is less margin to absorb downtime.
How to prepare
- Know your post-halving numbers now. Halve your current revenue per PH/day and compare it with your all-in cost per PH/day for each model you run, not a fleet average.
- Decide early on older machines. Machines that will be underwater after the halving are worth more sold, redeployed or parted out before it than after — see what to do with old ASIC miners.
- Look at tuning. Undervolting trades hashrate for efficiency and can pull a machine back above the line — see Overclocking vs Undervolting.
- Review power and hosting contracts. A contract that works at today’s hashprice may not work at half of it. Check minimum terms, curtailment rights and whether you pay for reserved power while machines are off.
- Protect uptime. With thinner margins, a week of downtime waiting for a power supply or hashboard costs a bigger share of the month’s profit. Keep critical spares on hand — see Cheap Part, Expensive Downtime.
Planning your fleet for the next halving?
Whether you need spare parts, hashboard repairs, or a buyer for older machines before their value drops, send us the miner model, quantity, condition and location, and we will put together a quote.
Hashprice reference: Hashrate Index Roundup, 28 September 2026. Figures are illustrative and assume price and network hashrate stay constant. Not financial advice.