Password Length Calculator

Choose an alphabet size and target bits to calculate the minimum uniformly random password length; this model does not estimate human-chosen password strength.

Target theoretical bits

Alphabet size

Preset

—Minimum length under a uniform independent-draw model

Sensitive values stay in this browser page. Theoretical entropy/search-space math assumes uniform random generation and is not a crack-time promise for human-chosen passwords. Use a reputable password manager for real account storage.

How to use this Password Length Calculator

Calculate the minimum length needed to reach a target theoretical random-password entropy. Enter your values above and the result is calculated directly in your browser. No account is required.

Fast answer, clear inputs

This tool is built around one job: give the answer quickly without forcing a signup or hiding the result. Related tools are linked nearby when the next calculation or conversion is useful.