Cohen's d
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
Cohen's d
About this calculator
The Cohen's d calculator is a useful tool for researchers and statisticians seeking to calculate the measure of effect size in comparisons between two groups.
This calculator uses the formula d = (μ₁ − μ₂)/σ_p, where μ₁ and μ₂ are the means of the two groups and σ_p is the combined standard deviation.
Cohen's d is an important measure in statistics, as it helps determine whether the differences between the groups are significant or not. It is particularly useful in case studies and research aiming to evaluate the effect of an intervention.
It is essential to note that the choice of effect size depends on the field of study and the amplitude of the data variations. Therefore, it is crucial to consider these factors when interpreting the results of the calculator.
Frequently asked questions
What is Cohen's d?
Cohen's d is a measure of effect size in comparisons between two groups, calculated based on the formula d = (μ₁ − μ₂)/σ_p.
When should I use the Cohen's d calculator?
It should be used in case studies and research that aim to evaluate the effect of an intervention.
What does the calculator result mean?
The result of the calculator indicates the magnitude of the effect between the two groups. A larger value indicates a greater effect.
How do I choose the effect size?
The effect size depends on the field of study and the amplitude of the data variations.