BTC: Breakeven Mining Efficiency
Shown as its 2019–2022 sample; the latest readings and full history are included with Plus.
The least efficient machine, in joules per terahash, whose revenue still covers its electricity at power prices of 3, 5 and 7 US cents per kWh, against the most efficient machine available.
Why use it. It tells miners which machines still earn money at their power price, and when a generation of machines is about to be switched off. How to read it. A machine with fewer J/TH than a line earns more than its electricity costs at that power price; one above the line loses money on every hash. When a line comes down to the most efficient machine, almost nobody is profitable at that price: a sign of miner stress.
Calculation. Breakeven efficiency = revenue per TH/s per day (USD) ÷ (0.024 kWh × power price × PUE 1.10). Revenue is the trailing seven days' claimed rewards ÷ their work, at the day's BTC/USD close. Each day uses the seven UTC days ending with it, to smooth block luck: hash rate is those blocks' work (difficulty × 2^32 each) over the window's seconds, and revenue per unit of hash rate is their claimed coinbase BTC (subsidy plus fees) over that work, at the day's BTC/USD close. A machine counts from the middle of the quarter its first units shipped, for four years (machines are written off over three to five years). It is profitable when its revenue covers its electricity at $0.05/kWh with a power usage effectiveness (PUE, the site's overhead for cooling and power conversion) of 1.10. The best guess is the plain average efficiency (J/TH) of the profitable machines, each model counted once; the lower bound puts all hash rate on the most efficient machine available, the upper bound on the least efficient profitable one; with no profitable machine all three use the most efficient. The model starts on 1 January 2014, when ASICs had replaced GPU and FPGA mining. It knows no real fleet: it assumes miners run machines that pay for their power and that every model is equally common, so cheap or free power, machines not yet installed, curtailment and each miner's real tariff move the true figure; the bounds show a reasonable range. It is an estimate, not a measurement. A model computed by CryptoKeyhole from its own Bitcoin node (each block's difficulty, claimed coinbase value, height and header time), the site's admitted BTC/USD daily closes, and a list of the main Bitcoin mining machines of Bitmain, MicroBT, Canaan, Bitdeer and Innosilicon from the first ASICs of 2013 to today, each with its manufacturer's nominal rating (TH/s and watts) and the quarter its first units shipped (the list: /api/v1/mining/hardware). Days are UTC days by block header time; the open day is partial. BTC/USD prices are the site's admitted boundary prices: daily closes from The Bitcoin Time Machine (CC BY 4.0) until 2 October 2026, then quotes recorded from Alternative.me at each boundary (within 15 minutes, never carried forward). Hourly values start on 3 October 2026, when hourly quotes begin.