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THE FEUTEX TOOLKIT

Tukey Inner and Outer Fences

Calculate boxplot screening fences from quartiles without deleting observations.

Statistics workspace● Runs in your browser
01 Your input
02 Your result
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FormulaLower Inner = q1-1.5*(q3-q1); Upper Inner = q3+1.5*(q3-q1); Lower Outer = q1-3*(q3-q1); Upper Outer = q3+3*(q3-q1)
Sources and model references

Made for real tasks

  • Calculate boxplot screening fences from quartiles without deleting observations.
Explore step-by-step workflows →

Worked example

Inputs

Lower quartile
10 number
Upper quartile
20 number

Expected results

Lower Inner
-5 number
Upper Inner
35 number
Lower Outer
-20 number
Upper Outer
50 number

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 lower quartile, upper quartile.
  2. Use the displayed units and confirm the model assumptions.
  3. Calculate and compare the outputs against your input scenario.

Try this example

{
  "q1": 10,
  "q3": 20
}

Accuracy and scope

Exploratory flags, not proof that observations are incorrect. Quartiles must already be computed.

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.