The breakeven power price, and why we ask for yours first

There is one number that settles more mining arguments than any other, and it is not the hashrate, the price of the machine or the coin price. It is the electricity price at which a given machine earns exactly what it costs to run. The revenue side of that comparison is hashprice, and it is worth reading first if the term is new. Once you know your price, the shortlist by power price turns it into a list of machines. Above that price it burns money every hour it is switched on. Below it, it contributes. Everything else is a question of how much.

What the number actually says

A miner turns electricity into revenue. Revenue depends on the network and the coin price, both outside your control. Cost depends on your power price and the machine's efficiency, both of which you decide when you sign. Set revenue equal to cost and solve for the power price, and you get a single figure in dollars per kilowatt hour that tells you whether this machine belongs on your site at all.

The useful property of that figure is that it is per machine, not per site. Two operators looking at the same model get the same breakeven. What differs is which side of it they sit on.

Working it out

You need three inputs: the machine's hashrate, its wall power, and the current revenue per unit of hashrate per day, usually quoted as hashprice. Daily revenue is hashrate times hashprice. Daily power cost is wall power times 24 hours times your rate. The breakeven rate is daily revenue divided by daily kilowatt hours.

Suppose a machine does 200 TH/s at 3,000 W, and hashprice sits at 5 US dollars per petahash per day. Daily revenue is 0.2 PH times 5, so one dollar. Daily consumption is 3 kW times 24 hours, so 72 kWh. Breakeven is one dollar divided by 72 kWh, about 1.4 cents per kilowatt hour. Those inputs are illustrative, but the arithmetic is the whole method: substitute your own and the answer takes a minute.

What moves it

• Hashprice. The dominant variable and the one you cannot influence. It moves with coin price and network difficulty, and it moves fast. A breakeven calculated today is a snapshot, not a forecast.
• Efficiency. The only lever on the cost side that hardware buys you. A machine at 12 J/TH tolerates roughly a third more expensive power than one at 16 J/TH, at any hashprice.
• Pool fees and uptime. Both cut revenue directly. A 2 percent fee and 95 percent uptime together move the breakeven by about 7 percent.
• Everything except electricity. Rent, staff, network, maintenance and insurance do not appear in the calculation, so the real threshold sits below the number you compute. Treat the result as a ceiling, not a target.

What it is good for

Shortlisting hardware, first. If your rate is 8 cents, machines whose breakeven sits at 4 cents are not a bargain at any purchase price, they are a slow loss. Site selection, second: the same fleet on two different power contracts can be a business or a total loss. And curtailment, third: when you know the breakeven, the decision to switch off during a price spike stops being a judgement call and becomes arithmetic.