Free Password Strength Calculator
Estimate password entropy in bits.
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Inputs
Result
Entropy
78.7 bits
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Estimates only. Verify with a professional for consequential decisions.
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Short answer
Estimate password entropy in bits.
What is the Password Strength Calculator?
Estimate password entropy in bits.
How does the Password Strength Calculator work?
Enter the inputs above and read the result.
Formula
Variables
LLengthNAlphabet size
Explanation
Assumes random character selection from the chosen pool.
Examples
Applications
Advantages
Limitations
Common mistakes
Tips
Related concepts
The Password Strength Calculator sits inside the Everyday & Utility Calculators hub, in the digital & misc utilities cluster. Security, sleep and other practical tools. Understanding the terms below makes the output easier to interpret and easier to compare against neighbouring measures.
Practical use cases and industry applications
Understanding Password Strength
Estimate password entropy in bits. Within everyday & utility calculators, password strength belongs to the digital & misc utilities cluster, where it shares terminology and assumptions with closely related tools.
Learning how password strength is calculated
Assumes random character selection from the chosen pool. Working through the variables one at a time — L, N — makes the result reproducible by hand and easier to sanity-check.
Using password strength to make a decision
Because outputs depend on the assumptions you enter, run more than one scenario before committing to a figure.
How password strength compares with related measures
entropy, bit strength, cycle length all describe adjacent aspects of digital & misc utilities. Comparing this calculator's output against those measures — using the related tools listed on this page — prevents a single metric from being read in isolation.
Frequently asked questions
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