Price per terahash ($/TH) is a miner's purchase price divided by its hashrate in TH/s. It tells you what each unit of mining capacity costs to buy, which makes machines of different sizes comparable. It says nothing about what that capacity costs to run, so a low $/TH is only a good deal if the machine's efficiency suits your electricity price.
Key points
- $/TH = purchase price ÷ hashrate (TH/s). A $2,000 machine at 200 TH/s costs $10 per TH.
- Total cost per TH over a period = $/TH + J/TH × 0.024 × days × price per kWh.
- The electricity price at which two machines cost the same is the difference in $/TH divided by (difference in J/TH × 0.024 × days).
- Cheap, less efficient machines win on cheap power and short horizons. Efficient machines win on expensive power and long horizons.
- Compare landed, installed cost per TH, not the listing price.
What price per terahash measures
Revenue in mining is earned per terahash: every TH/s on the network earns the same amount per day regardless of which machine produces it. $/TH is therefore the price of one unit of earning capacity. A 400 TH/s machine at $6,000 and a 200 TH/s machine at $3,000 are the same deal on this measure, $15 per TH, although one costs twice as much.
All prices in this guide are illustrative values chosen for easy arithmetic. Hardware prices move with the Bitcoin price and with difficulty, so request a current quote rather than relying on any published figure.
How to calculate it
- Take the price of the machine in one currency, on a stated basis (for example, before or after freight and import charges).
- Take the hashrate in TH/s. Use the manufacturer-published figure for a new machine and a measured figure for a used one.
- Divide price by hashrate.
When comparing quotes, make sure both use the same hashrate version of the model and the same delivery basis. A price that excludes freight will always look lower per TH than one that includes it.
Why $/TH must be read with J/TH
Buying cost is paid once. Electricity is paid every day, in proportion to efficiency (J/TH, the power in watts divided by the hashrate in TH/s). Each J/TH costs 0.024 kWh per TH/s per day, so over a period of T days at a price of p per kWh:
total cost per TH = $/TH + J/TH × 0.024 × T × p
Take two illustrative machines:
| Machine A | Machine B | |
|---|---|---|
| Hashrate | 200 TH/s | 240 TH/s |
| Power | 4,000 W | 3,600 W |
| Efficiency | 20 J/TH | 15 J/TH |
| Price (illustrative) | $2,000 | $3,840 |
| Price per TH | $10 | $16 |
Machine A is cheaper per TH by $6. Machine B uses 5 J/TH less. Compare per TH, not per machine, because the two have different hashrates and therefore different revenue.
Over two years (T = 730 days):
A: 10 + 20 × 0.024 × 730 × p = 10 + 350.4p
B: 16 + 15 × 0.024 × 730 × p = 16 + 262.8p
Set them equal and solve for p:
10 + 350.4p = 16 + 262.8p
87.6p = 6
p = $0.0685 per kWh
| Electricity price | A, total cost per TH over 730 days | B, total cost per TH over 730 days | Lower cost |
|---|---|---|---|
| $0.04 | $24.02 | $26.51 | A |
| $0.0685 | $34.00 | $34.00 | Equal |
| $0.10 | $45.04 | $42.28 | B |
Below $0.0685 per kWh, the cheaper machine costs less in total over two years. Above it, the efficient machine does.
The general formula is:
crossover price per kWh = difference in $/TH ÷ (difference in J/TH × 0.024 × T)
The crossover depends heavily on how long you expect to run the machines:
| Period | Crossover electricity price for A versus B |
|---|---|
| 365 days | $0.1370 |
| 730 days | $0.0685 |
| 1,095 days | $0.0457 |
| 1,460 days | $0.0342 |
The longer the horizon, the lower the power price at which the efficient machine pays for its premium.
What the comparison assumes
This calculation assumes both machines run continuously for the whole period, and it ignores resale value. Both assumptions favour the less efficient machine.
A less efficient machine has a lower break-even electricity price, so rising difficulty forces it off sooner. With the illustrative revenue of $0.0414 per TH per day used in How Bitcoin Mining Profitability Works, machine A breaks even at $0.0414 ÷ (20 × 0.024) = $0.086 per kWh and machine B at $0.0414 ÷ (15 × 0.024) = $0.115 per kWh. At $0.10 per kWh, A would already cost more to run than it earns. An efficient machine also tends to keep more resale value because it stays viable at more sites for longer.
What $/TH leaves out
The listing price is not the cost of having a machine hashing at your site. Add:
- Freight and insurance from the point of sale to your site.
- Import duties, taxes and brokerage, which depend on the destination country and the importer. See How to Import Bitcoin Miners.
- Power supply and cables. Check whether the listing includes the power supply and power cords for your region.
- Electrical infrastructure: circuits, PDUs (power distribution units), switchgear and, on larger sites, transformers.
- Cooling. Air-cooled machines need ventilation. Hydro machines need a coolant loop with pumps and a dry cooler or heat exchanger. Immersion machines need tanks and fluid. A hydro machine's $/TH covers the miner only.
- Racks, networking and installation labour.
Costs charged per machine weigh less on a higher-hashrate unit. If freight and import charges came to an illustrative $300 per machine, A's landed cost would be $2,300 ÷ 200 = $11.50 per TH and B's $4,140 ÷ 240 = $17.25 per TH: an extra $1.50 per TH for A and $1.25 for B.
Costs charged per kilowatt favour the efficient machine. Site infrastructure is sized by power, and each TH/s needs J/TH ÷ 1,000 kilowatts. At an illustrative $300 per kW of electrical and cooling infrastructure:
| Machine A (20 J/TH) | Machine B (15 J/TH) | |
|---|---|---|
| kW needed per TH/s | 0.020 | 0.015 |
| Infrastructure cost per TH | $6.00 | $4.50 |
On a power-limited site, efficiency also sets how much hashrate fits. One megawatt carries 50,000 TH/s at 20 J/TH and 66,667 TH/s at 15 J/TH, before cooling overhead.
New versus used
Used machines usually show a much lower $/TH than new ones. Three adjustments make the comparison fair:
- Use measured hashrate. A used machine with a 110 TH/s nameplate bought for an illustrative $600 is $5.45 per TH. If it actually hashes at 95% of nameplate, 104.5 TH/s, the real figure is $5.74 per TH.
- Account for efficiency. Used stock is mostly older generations with higher J/TH. Run the crossover formula at your power price and your expected running period.
- Price the risk. A used machine may have no remaining manufacturer warranty, an unknown service history and less remaining life. Budget for repairs and for a shorter period over which to recover the cost.
Low $/TH with high J/TH suits sites with very cheap power or a short planning horizon. High $/TH with low J/TH suits expensive power and long horizons. Neither is correct in general. New vs Used ASIC Miners covers condition checks in detail.