Hash Rate & Mining Time Calculator
Estimate how long a proof-of-work search takes from a hash rate and a target difficulty in leading zero bits.
How it works
Expected attempts = 2^difficulty bits · Expected time = expected attempts ÷ hash rate
In a proof-of-work search you hash candidate inputs until one produces a digest below a target — equivalently, one with a set number of leading zero bits. Because each hash is an independent random draw, the expected number of attempts to succeed is 2 raised to the number of required zero bits. Dividing that by your machine's hash rate gives the expected time; the actual time follows a geometric distribution, so any single search can finish much faster or slower than the average.
Worked example
A target of 40 leading zero bits needs on average 2⁴⁰ ≈ 1.1 × 10¹² hashes. A rig running at 100 MH/s (10⁸ hashes per second) would take about 1.1 × 10¹² ÷ 10⁸ ≈ 10,995 seconds, or roughly 3 hours, to find one.
Frequently asked questions
Is this specific to Bitcoin?
No — it is the generic proof-of-work relationship. Bitcoin expresses the same idea through a "difficulty" number, where expected hashes ≈ difficulty × 2³². Here you enter the target directly as leading zero bits, so it applies to any hash-based search or puzzle.
Why is the real time so variable?
Each hash succeeds with a fixed tiny probability, so the number of attempts is geometrically distributed. On average you need 2^bits tries, but with about 37% probability you exceed that, and occasionally you find one almost immediately.
What hash rate do real miners have?
Rates span an enormous range: a CPU manages millions per second (MH/s), a GPU billions (GH/s), and dedicated ASICs reach trillions to quadrillions (TH/s–PH/s). Pick the unit that matches your hardware.
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This calculator is for educational purposes. Double-check important results before acting on them.