Sample Size and Power Calculation for Bayesian Testing with Bayes Factor R package BayesPower version 1.0.4 The goal of 'BayesPower' is to provide tools for Bayesian sample size determination and power analysis across a range of common hypothesis testing scenarios using Bayes factors. The main function, BayesPower_BayesFactor(), launches an interactive 'shiny' application for performing these analyses. The application also provides command-line code for reproducibility. Details of the methods are described in the tutorial by Wong, Pawel, and Tendeiro (2025) <doi:10.31234/osf.io/pgdac_v3>. Software Imports: rlang, shiny, gsl, Rcpp, ExtDist, ggplot2, patchwork, rmarkdown, glue, hypergeo, rootSolve, shinyWidgets, grDevices, tidyr, scales LinkingTo: Rcpp, BH Tsz Keung Wong <t.k.wong3004@gmail.com> Comprehensive R Archive Network (CRAN) Tsz Keung Wong [aut, cre], Samuel Pawel [aut], Jorge Tendeiro [aut] GPL (>= 3) 2026-04-13 application/tgz https://CRAN.R-project.org/package=BayesPower doi:10.32614/CRAN.package.BayesPower