Free A-priori Sample Size Calculator for Multiple Regression

Thursday, August 28, 2008

A-priori Sample Size Calculator for Multiple Regression

This calculator will tell you the minimum required sample size for your study, given the alpha level, the number of predictors, the anticipated effect size, and the desired statistical power level.

For more information about this calculator, including method, formulae, and references, please click here.

Please supply the necessary parameters, and then click the 'Calculate' button.

Alpha Level: Also known as the p-value, probability, or type I error rate. By convention, this value should be less than or equal to 0.05 to claim statistical significance.

Number of Predictors: The total number of predictors in the model, not including the regression constant.

Anticipated Effect Size (f²): By convention, effect sizes of 0.02, 0.15, and 0.35 are considered small, medium, and large, respectively. To compute an effect size from an R², click here.

Desired Statistical Power Level: By convention, this value should be greater than or equal to 0.80.

The Statistics Calculators index now contains 50 free statistics calculators.

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