Password Search Space Calculator
Calculate the exact number of uniformly generated fixed-length strings and compare exhaustive-search time under your entered guess-rate assumptions.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Raise alphabet size to fixed length, calculate uniform entropy and compare distinct-guess counts with the resulting search space.
N=alphabet^length; uniform entropy=length×log₂(alphabet); mean guesses=(N+1)/2
Worked example
An alphabet of 10 with length 4 has 10000 possible strings and about 13.287712 bits of uniform entropy. At 1000 distinct guesses/second, full enumeration takes 10 seconds.
Assumptions and input details
This calculator accepts only counts, never an actual password. Uniform independent character choices and perfect distinct-guess enumeration are assumed. Human selection, reuse, breaches, dictionaries, hashing cost, account rate limits and imperfect parallel scaling are not measured. Example guess rates are editable numerical scenarios, not current hardware claims or a security certification.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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