Effect Size Calculator
Calculate Cohen's d, Hedge's g, and r effect size for statistical significance testing.
What Is the Effect Size Calculator?
Use this free online effect size calculator for instant, accurate results.
Formula
How to Use
Enter your values in the fields below and the result updates automatically.
Example Calculation
Enter sample values and click Calculate to see a worked example.
Understanding Effect Size
Effect Size Calculator is a free online tool providing instant, accurate calculations. No signup required.
All calculations run in your browser for maximum privacy and speed.
Bookmark this page for quick access to effect size calculator calculations whenever you need them.
Frequently Asked Questions
Is this calculator free?
Yes, completely free with no registration required.
How accurate are the results?
Results use standard mathematical formulas and are accurate to 6 significant figures.
Can I use this on mobile?
Yes, the calculator is fully responsive and works on all devices.
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