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THE FEUTEX TOOLKIT

Poisson Event Window

Estimate the probabilities of no events, one event or multiple events in a constant-rate window.

Probability workspace● Runs in your browser
01 Your input
02 Your result
View or copy raw result data
FormulaExpected Count = rate*t; None = exp(-rate*t); Exactly One = rate*t*exp(-rate*t); Two Or More = 1-exp(-rate*t)*(1+rate*t)
Sources and model references

Worked example

Inputs

Rate
2 events/time
Window
1.5 time

Expected results

Expected Count
3 events
None
0.04978706837 probability
Exactly One
0.1493612051 probability
Two Or More
0.8008517265 probability

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Enter the labeled inputs using consistent units.
  2. Check the stated assumptions and calculate.
  3. Review each output and compare another input scenario.

Try this example

{
  "rate": 2,
  "t": 1.5
}

Accuracy and scope

Independent events with constant rate; does not model clustering. Finite floating-point arithmetic; results can lose precision near singular or extreme inputs.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.