Designing Cluster-Randomized Trials with Two Continuous Co-Primary Outcomes R package crt2power version 1.2.2 Provides methods for powering cluster-randomized trials with two continuous co-primary outcomes using five key design techniques. Includes functions for calculating required sample size and statistical power. For more details on methodology, see Owen et al. (2025) <doi:10.1002/sim.70015>, Yang et al. (2022) <doi:10.1111/biom.13692>, Pocock et al. (1987) <doi:10.2307/2531989>, Vickerstaff et al. (2019) <doi:10.1186/s12874-019-0754-4>, and Li et al. (2020) <doi:10.1111/biom.13212>. Software Depends: R (>= 4.3) Imports: devtools (>= 2.4.5), knitr (>= 1.43), rootSolve (>= 1.8.2.3), tidyverse (>= 2.0.0), tableone (>= 0.13.2), foreach (>= 1.5.2), mvtnorm (>= 1.2), tibble (>= 3.2.1), dplyr (>= 1.1.4), tidyr (>= 1.3.0), stats (>= 3.6.2) Suggests: testthat (>= 3.0.0) Melody Owen <melody.owen@yale.edu> Comprehensive R Archive Network (CRAN) Melody Owen [aut, cre] GPL-3 2025-11-12 application/tgz https://CRAN.R-project.org/package=crt2power doi:10.32614/CRAN.package.crt2power