GRC's Interactive Brute Force Password “Search Space” Calculator

Every password you use can be thought of as a needle hiding in a haystack. After all searches of common passwords and dictionaries have failed, an attacker must resort to a “brute force” search – ultimately trying every possible combination of letters, numbers and then symbols until the combination you chose, is discovered.

If every possible password is tried, sooner or later yours will be found.
The question is: Will that be too soon . . . or enough later?

This interactive brute force search space calculator allows you to experiment with password length and composition to develop an accurate and quantified sense for the safety of using passwords that can only be found through exhaustive search.