Definition
A terahash per second (TH/s) is one trillion — 1012, or 1,000,000,000,000 — double-SHA-256 hash attempts every second. It is the practical unit for describing the output of an individual ASIC miner, because a single machine now performs trillions of guesses per second while searching for a block solution. When a spec sheet lists an Antminer S21 at roughly 200 TH/s, it means the unit attempts about 200 trillion candidate block headers each second.
Why terahash became the working unit
Hashrate scales with hardware generations. Early CPU and GPU miners were measured in megahashes and gigahashes; the move to purpose-built ASICs pushed per-machine output into the terahash range. Today a fleet's combined output is summed in terahashes before being rolled up into the larger units used for the whole network. Each hash is a guess: the chip assembles a block header, hashes it, and checks whether the result falls below the current target. More terahashes simply means more guesses per second and a proportionally higher chance of finding a valid golden nonce.
Terahash in efficiency and economics
Because raw speed alone does not pay the power bill, terahash is paired with other metrics. Efficiency is quoted in joules per terahash (J/TH), and revenue is benchmarked in sats per terahash. These ratios let operators compare a machine's productivity independent of its absolute size.
Terahash is the entry point in a chain of SI units; aggregating thousands of machines moves the conversation into petahash, exahash, and zettahash territory. For the broader family of rate measurements, see hashrate units.
Track total network hashrate in the live network vitals.
In Simple Terms
A terahash per second (TH/s) is one trillion — 1012, or 1,000,000,000,000 — double-SHA-256 hash attempts every second. It is the practical unit for describing…