ASIC Miner Power Consumption and J/TH: How to Calculate Costs
You can work out an ASIC miner's consumption from its power draw: a 3,500 W machine uses 84 kWh per day. Efficiency in J/TH tells you how much energy the miner needs per 1 TH/s of hashrate – the lower the number, the cheaper the mining. Current Bitcoin miners achieve 9.5–17.5 J/TH, the older Antminer S19 around 34 J/TH.
What J/TH means
J/TH (joules per terahash) is easy to calculate: divide the power draw in watts by the hashrate in TH/s. The Antminer S21++ delivers 235 TH/s at 3,760 W, i.e. 3,760 ÷ 235 = 16 J/TH. One watt is one joule per second, which is why J/TH also expresses how much energy one terahash costs.
Other algorithms use other hashrate units, but the principle is the same. The Scrypt-based Antminer L9 delivers 16 GH/s at 3,360 W, i.e. 210 J/GH. For Zcash (Equihash), efficiency is given in J/kSol. It only makes sense to compare machines on the same algorithm.
How to calculate consumption and costs
- Consumption per day (kWh) = power draw (W) × 24 ÷ 1,000.
- Cost per day = consumption (kWh) × electricity price (Kč/kWh).
- Revenue per day = hashrate × today's revenue per unit. On Bitcoin it is 0,84 Kč per 1 TH/s.
- Gross profit = revenue − costs. Remember to deduct the pool fee as well.
Example for the Antminer S21++ 235 TH/s (3,760 W) at today's difficulty and exchange rate, as of 18 Oct 2026:
| Item | Our hosting at 1.13 Kč/kWh | At home at 5 Kč/kWh (example) |
|---|---|---|
| Consumption per day | 90.2 kWh | 90.2 kWh |
| Electricity per day | 102 Kč | 451 Kč |
| Revenue per day (gross) | 197 Kč | 197 Kč |
| Difference per day | +95 Kč | −254 Kč |
The cheapest location of our hosting currently costs 1,13 Kč/kWh. Over 30 days the machine uses about 2,700 kWh, so every koruna on the price per kilowatt-hour makes a difference of 2,700 Kč a month.
Break-even electricity price for current miners
The break-even price is the electricity price at which a machine only just covers its costs. You calculate it as revenue per 1 TH/s per day ÷ (J/TH × 0.024). Values as of 18 Oct 2026, at revenue of 0.84 Kč per 1 TH/s:
| Model | Hashrate | Power draw | Efficiency | Consumption per day | Break-even price |
|---|---|---|---|---|---|
| Antminer S19k Pro | 120 TH/s | 2,760 W | 23 J/TH | 66.2 kWh | 1.52 Kč/kWh |
| Antminer S21 | 151 TH/s | 2,643 W | 17.5 J/TH | 63.4 kWh | 2.00 Kč/kWh |
| Antminer S21++ | 235 TH/s | 3,760 W | 16 J/TH | 90.2 kWh | 2.19 Kč/kWh |
| Antminer S21 Pro+ | 245 TH/s | 3,675 W | 15 J/TH | 88.2 kWh | 2.33 Kč/kWh |
| Antminer S21 XP Imm | 300 TH/s | 4,050 W | 13.5 J/TH | 97.2 kWh | 2.59 Kč/kWh |
| Antminer S23 Hyd | 563 TH/s | 5,349 W | 9.5 J/TH | 128.4 kWh | 3.68 Kč/kWh |
Revenue changes with network difficulty and the exchange rate; current figures for all models are shown in the ASIC miner profitability table.
What affects consumption
- Air temperature: in warm conditions the fans spin faster and the chips have higher losses, so efficiency drops.
- Measurement "at the wall": manufacturers such as Bitmain state the power draw at the PSU input at 25 °C, i.e. including PSU losses. The actual power draw may differ from the catalogue value depending on temperature and the individual unit.
- Mode and firmware: an eco mode reduces both power draw and hashrate, and J/TH usually improves. Overclocking does the opposite. More in the article Firmware and software for ASICs.
Why it matters for miners
Electricity is the biggest operating cost of mining, and efficiency decides how long a machine will keep earning. When choosing a miner, do not compare only TH/s – always look at power draw and J/TH as well. A more efficient generation survives a drop in revenue after the halving or a rise in difficulty with a bigger margin – see ASIC miner lifespan. How much energy Bitcoin mining consumes worldwide is covered in a separate article on Bitcoin mining energy consumption.
What next
If electricity is expensive for you at home, take a look at ASIC miner hosting in data centres. For a longer commitment, prepaid electricity helps, with a discount of 4% for 1 year, 12% for 3 years and 30% for 7 years.
Sources
Frequently asked questions
How much electricity does an ASIC miner use per month?
Is lower or higher J/TH better?
Does eco mode reduce a miner's consumption?
At what electricity price does Bitcoin mining pay off?
This text was prepared with the help of AI. Facts, figures and procedures were checked by Yegor.
