R effect size calculator
Use our r effect size calculator to calculate accurate size and measurement values instantly.
Calculator
Compute Cohen's d effect size from two means and pooled standard deviation.
Formula: d = (mean1 - mean2) / pooled SD
What each field means
- Mean 1: Enter a valid value for this field.
- Mean 2: Enter a valid value for this field.
- Pooled SD: Enter a valid value for this field.
Cohen d
Your result will appear here.
About R effect size calculator
The R effect size calculator helps you estimate sample size and statistics values quickly using consistent assumptions and practical calculation rules.
Formula Explanation
d = (mean1 – mean2) / pooled SD
Inputs You Need
- Required measurement values relevant to this calculator
- Unit selection: Mean 1, Mean 2, Pooled SD
- Optional tolerance, safety, or scenario values if applicable
Step-by-Step Usage
- Enter your known values in the calculator fields.
- Select units and options that match your scenario.
- Click Calculate to generate your output.
- Copy, save, or share the result for later reference.
Example
Run the tool with realistic values from your use case and compare the output against expected ranges for sample size and statistics calculations.
Method Sources
Frequently Asked Questions
Is this R effect size calculator accurate?
Yes, when correct inputs and units are provided.
Which units does this calculator support?
This tool is optimized for Mean 1, Mean 2, Pooled SD.
Can I use this calculator on mobile?
Yes, the form is optimized for touch inputs and smaller screens.