Hash Collision Probability Calculator
Estimate the birthday-bound probability that at least two uniformly distributed hashes collide.
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
Use the units printed beside each input and apply the stated convention exactly. Preserve the entered assumptions, then compare the baseline with the one-input sensitivity table.
p=100[1−exp(−n(n−1)/(2·2ᵇ))]
Worked example
Using the default inputs gives p = 0.0000027105027.
Assumptions and input details
This transparent calculator evaluates the stated model only. It does not infer calibration, measurement uncertainty, site conditions, biological suitability, safety margins, contractual limits or local rules. Confirm those separately when they affect a real decision.
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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