Hash Search Time Calculator
A brute-force search tries every possible value until it finds the one that produces a target hash. How long that takes depends on just two numbers: how many values are in the search space, and how fast your hardware can test them. This calculator divides the keyspace size by the hashing rate to give the total time to test every value exhaustively. If a space holds one billion candidates and a machine computes one million hashes per second, the full search takes one thousand seconds. The figure shown is the worst case; on average a single random target is found after testing about half the space, so the expected time is roughly half the total. Because a key of n bits has a space of two to the power n, each extra bit doubles the time, which is why even a few more bits make brute force impractical. Use it to reason about password cracking effort, the strength of a cryptographic key, or the cost of a search across a fixed set of inputs. Every figure is computed deterministically from your two inputs and converted into seconds, minutes, hours and days, with the method and a worked example shown below for verification.
Search time is the keyspace divided by the hashing rate: time = keyspace / hash rate. A space of 1,000,000,000 values tested at 1,000,000 hashes per second takes 1,000 seconds to search in full.
Hash search time formula
time (seconds) = keyspace / hash rate
keyspace = number of candidate values (2^n for an n-bit key)
hash rate = hashes tested per second
average time to find one target = time / 2
Dividing the full space by the rate gives the worst-case exhaustive time. Each extra key bit doubles the keyspace and so doubles the search time.
Worked example
A keyspace of 1,000,000,000 values is searched at 1,000,000 hashes per second.
- Time = keyspace / rate = 1,000,000,000 / 1,000,000
- Time = 1,000 seconds
- In minutes: 1,000 / 60 = 16.67 minutes
- Average time to find one target is about half, near 500 seconds
The full search takes 1,000 seconds. These are the calculator's default inputs, so the result above matches the widget exactly.
Keyspace by bit length
Each added bit doubles the number of candidates.
| Key bits | Keyspace (2^n) |
|---|---|
| 16 | 65,536 |
| 24 | 16,777,216 |
| 30 | 1,073,741,824 |
| 40 | 1,099,511,627,776 |
Cryptographic key strength concepts: US National Institute of Standards and Technology (NIST).
Hash search time calculator: frequently asked questions
How long does it take to search a keyspace?
The search time is the size of the keyspace divided by the number of hashes computed per second. If a keyspace holds one billion values and a machine tests one million per second, it takes one billion divided by one million, which is 1,000 seconds to test them all.
Is this the average or the worst case?
Dividing the full keyspace by the rate gives the worst case, the time to test every value. On average a single random target is found after testing about half the keyspace, so the expected time is roughly half the figure shown. This calculator reports the full exhaustive time.
How does keyspace relate to bit length?
A key of n bits has a keyspace of 2 to the power n. Each added bit doubles the space and therefore doubles the search time. This is why a small increase in key length makes brute-force search exponentially harder.
What units does the result use?
The calculator shows the total time in seconds and also converts it into minutes, hours and days for readability. Very large keyspaces can produce times longer than the age of the universe, which is the point of strong cryptographic keys.
Is the result computed automatically?
Yes. The page divides the keyspace by the hash rate deterministically. No figure is estimated or hard-coded, so changing either input updates the answer instantly.
Official sources
- Cryptographic key strength and hashing concepts: US National Institute of Standards and Technology (NIST). As at 25 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 25 June 2026. See our methodology. This is general information, not financial, tax, legal or investment advice.