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Calcimator

Effect Size Calculator

Calculate Cohen's d, Hedges' g, and Glass's delta to measure the practical significance of differences between two groups.

Inputs

Results

Cohen's d

0.54

Hedges' g (bias-corrected)

0.54

Glass's Delta (Δ)0.5
Pooled Standard Deviation11.05
Common Language Effect Size0.65
Point-Biserial r0.26
Size (0=negligible, 1=small, 2=med, 3=large, 4=very large)2
How to Use This Calculator
  1. Enter Group 1 Mean, Group 2 Mean, and Group 1 Standard Deviation.
  2. Set Group 2 Standard Deviation, Group 1 Sample Size, and Group 2 Sample Size.
  3. Review Cohen and Hedges.
  4. Use Glass and Pooled Standard Deviation to inform your decision.
  5. Use the chart to visualize the results and explore different scenarios by adjusting inputs.

How the result changes with Group 1 Mean

Group 1 MeanCohen's dHedges' g (bias-corrected)
-800,000-72,435.12-71,494.4
-300,000-27,167.24-26,814.42
300,00027,154.2126,801.55
800,00072,422.0871,481.53

What each input means

Group 1 Mean
Mean of the first (treatment or experimental) group.
Group 2 Mean
Mean of the second (control or comparison) group.
Group 1 Standard Deviation
Standard deviation of the first group.
Group 2 Standard Deviation
Standard deviation of the second group.
Group 1 Sample Size
Number of observations in the first group.
Group 2 Sample Size
Number of observations in the second group.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Group 1 Mean = 78, Group 2 Mean = 72, Group 1 Standard Deviation = 10, Group 2 Standard Deviation = 12 = 6 input(s) provided
  2. Calculate Cohen's d
    Cohen's d
    0.5432 = 0.5432
  3. Calculate Hedges' g
    Hedges' g
    0.5362 = 0.5362
  4. Calculate Glass's Delta
    Glass's Delta
    0.5 = 0.5
  5. Calculate Pooled Standard Deviation
    Pooled Standard Deviation
    11.0454 = 11.0454

Engine last updated . Checked against 2 independently-derived tests — how we verify calculators.

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