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THE FEUTEX TOOLKIT

Pooled Standardized Mean Difference

Compare group means in pooled-standard-deviation units using two independent sample summaries.

Statistics workspace● Runs in your browser
01 Your input
02 Your result
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FormulaPooled Sd = sqrt(((n1-1)*s1**2+(n2-1)*s2**2)/(n1+n2-2)); Standardized Difference = (m1-m2)/sqrt(((n1-1)*s1**2+(n2-1)*s2**2)/(n1+n2-2))
Sources and model references

Worked example

Inputs

M1
12 number
M2
10 number
Group 1 SD
2 value
Group 2 SD
2 value
Group 1 size
20 count
Group 2 size
20 count

Expected results

Pooled Sd
2 number
Standardized Difference
1 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 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

{
  "m1": 12,
  "m2": 10,
  "s1": 2,
  "s2": 2,
  "n1": 20,
  "n2": 20
}

Accuracy and scope

Independent groups and common-scale measurement. Raw standardized difference without a small-sample correction. 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.