Password Entropy Calculator
Entropy bits and crack time.
Enter your values
Results update instantly as you type — no submit needed.
Results
- Entropy
- 91.8 bits
- Time to crack
- 667497127 years
- Combinations
- 4.205e+27
- Rating
- Strong
Quick answer
Password entropy measures unpredictability in bits; each extra bit doubles the search space.
Entropy = length × log2(character set)
How to use the Password Entropy Calculator
- 1Enter the password length.
- 2Choose the character set used.
- 3Adjust attacker guess rate for your threat model.
Frequently asked questions
How many bits is enough?
80+ bits resists offline attacks for the foreseeable future.
Are passphrases better?
Yes — four random words beat a short complex password.