How to use the Password Crack Time Calculator
- 1. Describe the passwordChoose length and character types, or type a test password.
- 2. Set the attack speedEnter guesses per second for the scenario you want to model.
- 3. Read the timeSee average and worst-case time, entropy and any warnings.
The maths
For a random password, the number of possible combinations is N^L, where N is the size of the character pool and L is the length. Entropy is L × log₂(N) bits. On average an attacker finds it after searching half the space, so average time = N^L ÷ 2 ÷ guesses per second.
Worked example: 12 random characters from all 94 printable letters, digits and symbols give 94¹² ≈ 4.76 × 10²³ combinations and 78.66 bits of entropy. At 10 billion guesses per second the average time is about 754,050 years. Drop to 8 lowercase letters and the same attacker needs only about 10 seconds.
Why real passwords fall faster
Brute force is the worst case for an attacker. In practice they start with leaked password lists, dictionary words, names, dates and rules like "capital first, number and symbol at the end". A password such as Sunrise@2024 looks strong by length but follows a pattern crackers try early. The calculator warns about common passwords, years, repeats and keyboard runs, but it cannot spot every pattern.
- Attack speed is an assumption you set. Throttled online logins allow very few guesses; offline attacks on fast, unsalted hashes run billions per second on modern GPUs; slow hashes like bcrypt cut that enormously.
- Length beats complexity: a long random passphrase is both stronger and easier to type.
- Use a password manager and unique passwords everywhere, plus MFA.
Your password never leaves the page and is not stored. Generate a strong one with the password generator, and see how sites should store it with the bcrypt hash generator.
Frequently asked questions
Should I type my real password?
It never leaves your browser, but the safest habit is to test a similar password, not your real one.
Why does adding one character matter so much?
Each extra character multiplies the combinations by the pool size, 94 times for full printable ASCII.
Is the Password Crack Time Calculator free?
Yes, the Password Crack Time Calculator is free. The first time you see your first estimate, you are asked for your name and WhatsApp number once. After that, this and every other Uncodemy tool opens straight away without the form.