Exponential Waiting Time Calculator
Calculate survival, cumulative probability and density for a constant-rate exponential waiting model.
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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 a constant nonnegative hazard and the same time unit for elapsed time and rate denominator.
Survival=exp(−rate×time); CDF=1−survival; mean=1/rate
Worked example
A rate 0.5 per hour gives probability exp(−1)≈0.367879441 of waiting longer than two hours, with mean wait two hours.
Assumptions and input details
Continuous constant-hazard independent-event model; rate is entered, not estimated. Density has reciprocal-time units and is not a point probability.
References: NIST: probability distributions
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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