Password Strength Calculator
Shows how length and character set change the time needed to guess a random password.
Average time to find it
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Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
Time to try every combination —
Entropy — bits
Rule-of-thumb band —
Reading this —
The formula
bits = length × log₂(set size) time = 2^bits ÷ guesses per second
On average an attacker finds it about halfway through, so the average time is half the full time.
What to watch out for
A password manager can generate and remember a long random password for each account.
Frequently Asked Questions
How long does a random 8-character password last?
Using 94 characters at 10 billion guesses a second, every combination takes 7 d 1 h 19 min 29 s.
And a random 16-character one?
At the same speed, about 10^14 years.