Dieser Artikel ist auf Englisch.
What J/TH means
A joule per second is a watt, and a terahash per second is one TH/s, so J/TH is also watts per TH/s. A machine’s draw is its efficiency times its hashrate:
Power (W) = efficiency (J/TH) × hashrate (TH/s). An Antminer S21 Pro: 15 × 234 = 3,510 W. An Antminer S23 Hyd: 9.5 × 580 = 5,510 W.
Two machines with the same hashrate can draw very different power, and the bill follows the power, not the hashrate. That is why every machine in the miner catalogue lists J/TH next to its price.
From J/TH to a monthly bill
A month is about 730 hours (30.4 days × 24), so each J/TH uses 0.73 kWh per TH/s a month. At Segments’ hosting rate of 6.0¢/kWh:
| Efficiency | kWh per TH a month | Power per TH a month at 6.0¢ | For example |
|---|---|---|---|
| 9.5 J/TH | 6.9 | $0.42 | Antminer S23 Hyd |
| 12 J/TH | 8.8 | $0.53 | Antminer S21 XP Hyd |
| 13.5 J/TH | 9.9 | $0.59 | Antminer S21 XP |
| 15 J/TH | 10.9 | $0.66 | Antminer S21 Pro |
| 17.5 J/TH | 12.8 | $0.77 | Antminer S21 |
| 21.5 J/TH | 15.7 | $0.94 | Antminer S19 XP |
Scale it up by the hashrate for the whole machine: an S21 Pro (234 TH/s at 15 J/TH) uses about 2,560 kWh in a month of running, $154 at 6.0¢.
The efficiency bands
Machines fall into bands by generation, and each band has its own power bill per terahash:
| Band | Typical machines | Power per TH a month at 6.0¢ |
|---|---|---|
| Under 14 J/TH | Antminer S23 series, S21 XP, S21 XP Hyd, S21e XP Hyd | under $0.61 |
| 14–19 J/TH | Antminer S21, S21 Pro, S21 Hyd | $0.61 to $0.83 |
| 19–25 J/TH | Antminer S19 XP, S19 XP Hyd | $0.83 to $1.09 |
| 25–38 J/TH | Antminer S19 Pro, S19j Pro | $1.09 to $1.66 |
| 38 J/TH and above | Older generations | $1.66 and more |
The spec sheet and the wall socket
- Typical, not exact. Makers quote a typical figure and allow about ±5% on power and ±3% on hashrate per unit, so two machines of one model can differ by a few per cent.
- Measured at the wall. Current spec sheets give power at the wall, power supply included. Some older listings quoted the chips alone, which flatters the figure.
- Heat costs efficiency. Hot chips draw more for the same work, and air-cooled machines also run fans. Hydro-cooled machines hold their chips at a steady temperature through a Gulf summer, which is part of why the most efficient models are hydro. See cooling in Gulf heat.
- Firmware moves it. Underclocking lowers J/TH and hashrate together; overclocking raises both. Ask your hosting provider which profile your machine runs.
When efficiency matters more than price
What a terahash earns, the hashprice, moves with the Bitcoin price and difficulty. What it costs in power does not. The share of revenue left after power is:
Left after power = 1 − (J/TH × 0.024 × rate) ÷ hashprice per TH a day. On 31 October 2026, with a hashprice near $0.033 per TH a day, an S21 Pro kept about 34% and an S23 Hyd about 58%, both at 6.0¢.
- Hashprice
- $0.0327 pro TH/s und Tag
The lower the hashprice and the higher your rate, the larger the part of the result J/TH decides, and the more a lower-J/TH machine is worth per terahash. For the S23 against the S21 range in full, read the S23 vs S21 power bill; for any model at your own rate, use the profitability calculator.
Fragen
- What does J/TH mean on a Bitcoin miner?
- Joules per terahash: the energy the miner uses for each terahash of work, which is the same as watts per TH/s. Lower J/TH means less power for the same hashrate.
- How do I work out a miner’s power from J/TH?
- Multiply J/TH by the hashrate in TH/s to get watts. An S21 Pro at 15 J/TH and 234 TH/s draws 3,510 W, about 2,560 kWh in a month of running.
- What is a good J/TH in 2026?
- The newest machines run under 14 J/TH, with the Antminer S23 series at 9.5 J/TH or lower. The S21 generation runs from about 12 to 17.5 J/TH, and older S19 machines above 19.
- Does a lower J/TH always mean a better buy?
- No. A lower-J/TH machine usually costs more per terahash, so weigh the power it saves against the higher price. The share of revenue left after power, at your own rate, is the figure to compare.