Password strength is measured by entropy, which represents the mathematical difficulty of guessing a password by brute force. Entropy depends on two major factors: the length of the password and the size of the character pool (uppercase, lowercase, digits, symbols). To generate safe cryptographic keys instead of text passwords, try our
RSA Key Generator. Here is the standard password entropy mapping:
# Password Entropy Formula
Entropy (bits) = Length * log2(Character Pool Size)
- Less than 50 bits : Weak (easy to crack)
- 50 to 80 bits : Medium / Good
- Over 80 bits : Strong (extremely secure)