Menu

Effect Size (Cohen's d) Calculator

Effect Size Calculator for T-test
Group 1
Mean, M1
Standard Deviation, SD1
Group 2
Mean, M2
Standard Deviation, SD2
Results
Cohen's d = 0.242

Please provide a rating, it takes seconds and helps us to keep this resource free for all to use

[ 13 Votes ]

The Effect Size (Cohen's d) Calculator is a useful tool for measuring the difference between two groups or conditions in a study. By calculating the effect size using Cohen's d, you can determine the magnitude of the difference between two groups or conditions, independent of sample size. In this tutorial, we will provide step-by-step instructions on how to use the calculator, some interesting facts about effect size, and the formula used to calculate the effect size using Cohen's d.

Interesting Facts:

  • Effect size is a statistical concept that measures the strength of a relationship between two variables or the magnitude of a difference between two groups or conditions.
  • Cohen's d is a widely used effect size measure that expresses the difference between two means in standardized units.
  • The interpretation of Cohen's d values depends on the context of the study, but a rule of thumb is that values of 0.2, 0.5, and 0.8 represent small, medium, and large effect sizes, respectively.

Formula:

The formula used to calculate the effect size using Cohen's d is:

d = (mean1 - mean2) / spooled

where mean1 and mean2 are the means of the two groups or conditions, and spooled is the pooled standard deviation, calculated as:

spooled = sqrt((n1 - 1) * s12 + (n2 - 1) * s22) / (n1 + n2 - 2)

where s1 and s2 are the standard deviations of the two groups or conditions, and n1 and n2 are the sample sizes of the two groups or conditions.

Results:

The Effect Size (Cohen's d) Calculator is a valuable tool that can help you calculate the effect size between two groups or conditions in a study. By following the step-by-step instructions in this tutorial, you can easily determine the magnitude of the difference between two groups or conditions

Math Calculators

You may also find the following Math calculators useful.