Sample Size Calculator for Survival Endpoint Clinical Trials R package survSampleSize version 0.1.2 An interactive 'shiny' application for sample size and power calculation under general conditions for clinical trials with survival endpoints. Implements the weighted log-rank method of Lu (2021) <doi:10.1002/pst.2069> via the 'lrstat' package, supporting non-proportional hazards, delayed treatment effects, unequal allocation and dropout, as well as the classic method of Freedman (1982) <doi:10.1002/sim.4780010204> via the 'powerSurvEpi' package. Results are presented interactively with survival curves and event-prediction timelines. Software Imports: lrstat, powerSurvEpi, shiny, stats Suggests: bslib, DT, ggplot2, knitr, plotly, rmarkdown, testthat (>= 3.0.0) Huai Jiang <13661928191@163.com> Comprehensive R Archive Network (CRAN) Huai Jiang [aut, cre] MIT + file LICENSE (https://CRAN.R-project.org/package=survSampleSize/LICENSE) 2026-06-21 application/tgz https://CRAN.R-project.org/package=survSampleSize doi:10.32614/CRAN.package.survSampleSize