Formula
Pool size = selected lowercase + uppercase + digits + symbols. Search space = pool size^length. Entropy bits = length × log2(pool size).
Developer & IT
Password Generator
Generate a deterministic password-strength estimate from length and character sets, with entropy bits, search-space size and safety notes for using a real password manager.
Developer & IT
Password Generator
Live answer104.9 bits16 characters from 94 possible characters · search space about 10^31.6 · very strong random setting. Use a password manager for real secrets.
Live result104.9 bits16 characters from 94 possible characters · search space about 10^31.6 · very strong random setting. Use a password manager for real secrets.
Formula used
Pool size = selected lowercase + uppercase + digits + symbols. Search space = pool size^length. Entropy bits = length × log2(pool size).
This is the method behind the answer, so the result can be checked rather than simply trusted.Visual grid
This number is one point on a larger pattern
Password Generator is not just a final answer. It is a step on a line: before and after, input and output, assumption and result.
Micro-timehours, minutes, shiftsHuman scaledays, weeks, projectsMacro-timemonths, years, calendars
InputFormulaResult
104.9 bitsCalculationTime keeps the path visible: the input, the method and the final number belong together.
CalculationTime
Password Generator Calculation Report
104.9 bits16 characters from 94 possible characters · search space about 10^31.6 · very strong random setting. Use a password manager for real secrets.
Inputs
- Password length
- 16 characters
- Lowercase letters
- 1
- Uppercase letters
- 1
- Digits
- 1
- Symbols
- 1
Method
Pool size = selected lowercase + uppercase + digits + symbols. Search space = pool size^length. Entropy bits = length × log2(pool size).
- A 16-character password using lowercase, uppercase, digits and symbols has a pool around 94 characters. Entropy is 16 × log2(94), about 104.9 bits.
Assumptions
- The entropy estimate assumes truly random independent character selection.
- Human-made passwords, reused passwords and dictionary-based passwords can be much weaker.
- This page is for strength estimation; use a trusted password manager to generate and store real secrets.
- Do not send real passwords to chat, email or screenshots.
Notes
Use this space on the printed report for client, supplier, classroom, job-location, measurement, quote or approval notes.
Worked example
A 16-character password using lowercase, uppercase, digits and symbols has a pool around 94 characters. Entropy is 16 × log2(94), about 104.9 bits.
Professional note
Master’s Tip: length beats cleverness. A long random password stored in a password manager is better than a short memorable pattern with substitutions.
Regional and unit assumptions
General information-security arithmetic for random password search space; not a guarantee against phishing, malware, database leaks or password reuse.
Assumptions and limitations
- The entropy estimate assumes truly random independent character selection.
- Human-made passwords, reused passwords and dictionary-based passwords can be much weaker.
- This page is for strength estimation; use a trusted password manager to generate and store real secrets.
- Do not send real passwords to chat, email or screenshots.
Methodology & Accuracy
How this calculator is checked
CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.
Formula used
Pool size = selected lowercase + uppercase + digits + symbols. Search space = pool size^length. Entropy bits = length × log2(pool size).
Standard or basis
General information-security arithmetic for random password search space; not a guarantee against phishing, malware, database leaks or password reuse.
Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.Master's Tip
Master’s Tip: length beats cleverness. A long random password stored in a password manager is better than a short memorable pattern with substitutions.
Related calculators
Questions
Does this page save passwords?
No. The calculator estimates strength from settings. For real passwords, use a password manager.
How many bits is strong?
For ordinary account passwords, long random passwords around 80+ bits are generally far stronger than human-memorable patterns, but threat models vary.
Are symbols required?
Symbols help by increasing the character pool, but length and randomness usually matter more than satisfying one symbol rule.
Calculation note
Password strength is often misunderstood as decoration rules. Search-space arithmetic shows why long random strings are easier to defend than short clever words.
Sources and further readingNIST SP 800-63B — Digital Identity Guidelines