Sample Size Calculation for Various t-Tests and Wilcoxon-Test

Computes sample size for Student's t-test and for the Wilcoxon-Mann-Whitney test for categorical data. The t-test function allows paired and unpaired (balanced / unbalanced) designs as well as homogeneous and heterogeneous variances. The Wilcoxon function allows for ties.

To install the development version of the samplesize package, it is easiest to use the devtools package:

install.packages("devtools")  # if needed..
install_github("samplesize", "shearer")


Reference manual

It appears you don't have a PDF plugin for this browser. You can click here to download the reference manual.


0.2-4 by Ralph Scherer, 2 years ago

Report a bug at

Browse source code at

Authors: Ralph Scherer

Documentation:   PDF Manual  

Task views: Clinical Trial Design, Monitoring, and Analysis

GPL (>= 2) license

See at CRAN