Technology & IT

Password Entropy Calculator

Estimate theoretical password entropy from length and available character sets.

Free toolGlobal unitsInstant calculation

Calculator

Result

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Formula: Theoretical entropy = password length × log₂(character-set size). It assumes independent uniformly random characters and is not a guarantee of real-world security.

About this calculator

This is a mathematical entropy estimate, not a password-strength guarantee. Real passwords often have patterns and are less random than the model assumes.

Enter valid values, then select Calculate. The calculation runs in your browser and does not require an account.

How to use this calculator

What to enter

Enter or select the following as requested: Password length; Character-set size. Follow the units, valid ranges, examples, and options displayed beside each field.

What the result means

The output is the transformed value, generated snippet, lookup result, or technical measurement produced from the supplied input and selected options. Review the output before using it, and verify compatibility with the target system or format.

When to use it

Use this as a developer or technical utility for encoding, conversion, validation, calculation, or reference. Do not treat a successful transformation as proof that a system is secure or that generated code is production-ready.