Random Password Entropy
Count uncertainty for independent uniformly random character choices.
Your numbers
Generation entropy
Applies only to independent uniform random generation, not human-chosen passwords. Do not enter an actual password; no password field exists.
Scenario comparison
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Formula
Use H = L×log₂(A). L is the independently sampled password length, A is the alphabet size, and H is entropy in bits.
Count uncertainty for independent uniformly random character choices.
Worked example
- Random character count
- 12
- Alphabet size
- 64
- Generation entropy
- 72 bits
Scope and limitations
Applies only to independent uniform random generation, not human-chosen passwords. Do not enter an actual password; no password field exists.
Inputs are checked for missing values and allowed ranges. A result outside the finite numeric range is not displayed. Rounding affects display, while the calculation uses the model’s numeric precision.
Check your units and assumptions before relying on a result. Changing a label does not convert a currency or physical unit.
Formula version: 4a185c88e00c · Example checked: