Power and Sample Size Tools
Power calculation for precision analysis (confidence interval) for a d...
Power calculations for multiple co-primary continuous endpoints assumi...
Power calculations for multiple co-primary continuous endpoints assumi...
Power calculation for test of one correlation coefficient
Power calculation for comparing two correlation coefficients
Power for test of treatment effect in longitudinal cluster randomized ...
Correlation between a cluster mean at baseline and follow up
Cohen f effect size calculation for one- or two- way analysis of varia...
Cohen d effect size calculation for one or two means
Cohen f-squared effect size for overall F test in multiple linear regr...
Power calculation for multiple alternative (at least one) primary cont...
Power calculation for one-way balanced analysis of variance contrast t...
Power calculation for one-way unbalanced analysis of variance contrast...
Power calculation for balanced one-way ANOVA omnibus F test
Power calculation for unbalanced one-way analysis of variance omnibus ...
Power calculation for two-way balanced analysis of variance contrast t...
Power calculation for two-way unbalanced analysis of variance contrast...
Power calculation for two-way balanced analysis of variance F tests
Power calculation for two-way unbalanced analysis of variance F tests
Power calculation for test of simple effect for two-way balanced analy...
Power calculation for test of simple effect for two-way unbalanced ana...
Internal-use function for quality checking sets of parameters
Internal-use function for quality checking individual parameters
Power calculation for chi-square goodness-of-fit test
Power calculation for chi-square test of independence
Power calculation for precision analysis (confidence interval) for one...
Power calculation for cluster randomized trial with binary outcome
Power for cluster randomized trial with continuous outcome
Power for detecting treatment effect heterogeneity in a cluster random...
Variance exploration for cluster randomized trials with binary outcome...
Power for test of treatment effect in 2x2 crossover cluster randomized...
Cohen f-squared effect size for partial F test in multiple linear regr...
Cohen h effect size calculation for two proportions
Cohen q effect size calculation for two correlation coefficients
Cohen w effect size calculation for chi-square tests
Power for individual randomized group treatment trial with binary outc...
Power for individually randomized group treatment trial with continuou...
Power for detecting treatment effect heterogeneity in an individually ...
Internal-use function for displaying matrices in function outputs
Power calculation for a multiple linear regression overall F test
Power calculation for a multiple linear regression partial F test
Variance exploration for a multisite trial with a binary outcome
Power for a multisite trial with a binary outcome
Power for test of average treatment effect in a multisite trial
Power for test of heterogeneity of treatment effect in a multisite tri...
Power calculation for one-sample proportion test
Power calculation for two-sample proportion test
Power calculation for McNemar test of two correlated proportions
Power calculation for test of equivalence of two proportions
Power calculations for ordinal categorical variable under proportional...
Power calculation for rank-sum test
Power calculation for paired t test
Relative efficiency of a cluster randomized or multisite trial with bi...
Relative efficiency of a cluster randomized or multisite trial with co...
Power calculation for relative risk
Internal-use wrapper for catching errors induced by stats::uniroot
Power calculation for signed-rank test
Power calculation for sign test
Power calculation for a simple linear regression
Power calculation for one-sample t test
Power calculation for two-sample t test
Power calculation for one-sample z test
Power calculation for two-sample z test
Power calculation for paired z test
Power and sample size calculations for a variety of study designs and outcomes. Methods include t tests, ANOVA (including tests for interactions, simple effects and contrasts), proportions, categorical data (chi-square tests and proportional odds), linear, logistic and Poisson regression, alternative and coprimary endpoints, power for confidence intervals, correlation coefficient tests, cluster randomized trials, individually randomized group treatment trials, multisite trials, treatment-by-covariate interaction effects and nonparametric tests of location. Utilities are provided for computing various effect sizes. Companion package to the book "Power and Sample Size in R", Crespi (2025, ISBN:9781138591622). Further resources available at <https://powerandsamplesize.org/>.
Useful links