Password Combinations Calculator
Count the total number of possible passwords for a given length and character set, and see the entropy in bits.
How it works
combinations = charset ^ length · entropy bits = length × log₂(charset)
The number of distinct passwords is the character-set size raised to the length, because every position can independently be any of the available symbols. Expressing that count in bits — the base-2 logarithm — gives entropy, the standard yardstick for password strength: each bit doubles the number of possibilities. This count is the raw defence against brute force; how long cracking actually takes then depends on the attacker’s guessing speed.
Worked example
An 8-character password using all 95 printable ASCII symbols has 95⁸ ≈ 6.6×10¹⁵ combinations, which is 8 × log₂(95) ≈ 52.6 bits of entropy.
Sources: Password entropy — Wikipedia
Frequently asked questions
What counts as good entropy?
As a rough guide, under 40 bits is weak, 60–80 bits is reasonable for most accounts, and 100+ bits is strong even against well-funded attackers. Entropy assumes the password is chosen truly at random from the set.
Does using symbols beat using a longer password?
Length usually wins. Going from a 62-symbol to a 95-symbol set adds only about 0.6 bits per character, whereas each extra character of any set adds log₂(charset) bits — often more, and it is easier to remember.
Why is my real password weaker than this number suggests?
This assumes every character is picked at random. Human-chosen passwords follow patterns — dictionary words, dates, keyboard runs — that attackers exploit, so real-world entropy is far lower than the theoretical maximum.
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This calculator is for educational purposes. Double-check important results before acting on them.