Random ID Space Planner
Calculate possible random identifiers and entropy for an alphabet and length.
Your inputs
Calculation results
Formula & assumptions
Possible IDs = alphabet size^length; entropy = length × log₂(alphabet size).
Values use the specified units. Calculations use floating-point arithmetic. Check input measurements and formula assumptions before applying the result.
Compare your scenarios
Save up to five results to compare changes side by side. Scenarios stay in this tab until you clear or reload it.
Using Random ID Space Planner
Calculate possible random identifiers and entropy for an alphabet and length.
- Enter alphabet size, identifier length using the units printed under each field.
- Choose Calculate, or enable live updates. Review the result labels and formula assumptions.
- Save scenarios to compare up to five variations, then copy the report or download JSON or CSV.
Example
Alphabet size: 62 symbols Identifier length: 12 symbols Entropy · bits: 71.450356 Log10 possible identifiers: 21.5087 Characters: 12
Questions & answers
What does Random ID Space Planner calculate?
Calculate possible random identifiers and entropy for an alphabet and length.
Which units should I enter?
Alphabet size uses symbols. Identifier length uses symbols. Convert values to these units before calculating.
Which formula does it use?
Possible IDs = alphabet size^length; entropy = length × log₂(alphabet size).
What does the included example show?
Alphabet size: 62 symbols; Identifier length: 12 symbols. Result: Entropy · bits = 71.450356; Log10 possible identifiers = 21.5087; Characters = 12.
Can I compare different settings?
Yes. Save a scenario, change the inputs and save another result. Up to five scenarios are compared in this tab; they disappear when you reload or leave.
Can I export the calculation?
Copy the JSON report or download JSON and CSV with inputs, result labels and numeric values. Processing uses local JavaScript; no calculation request is sent to our server. Displayed values use up to 10 significant digits; exports retain JavaScript numeric precision.
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