Cohen's d Effect Size Calculator Helper: Mean, Sample SD, and Group Size Inputs from Raw Data
Use the calculator to summarize each group from raw data, then compute the mean difference, sample SD, and sample size inputs needed for Cohen's d and pooled standard deviation workflows. Useful for A/B tests, classroom comparisons, and two-group research reporting.
12 values
Instant Math
Use when your data represents a subset of a larger population. Applies Bessel's correction.
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Input your numbers into the Standard Deviation Calculator panel to see real-time statistics, variance, and normal distribution charts.