»  Home »  Products »  Features »  Power and sample size
Order Stata

Power and sample size

Before you conduct your experiment, determine the sample size needed to detect meaningful effects without wasting resources. Do you intend to perform tests of means, variances, proportions, or correlations? Do you plan to fit a one-way, two-way, or repeated-measures ANOVA model? Do you want to fit a Cox proportional-hazards model or compare survivor functions using a log-rank test or exponential regression? Use Stata's power commands or interactive Control Panel to compute power and sample size, create customized tables, and automatically graph the relationships between power, sample size, and effect size for your planned study. And much more.

Classic comparisons

  • Means (t-tests) Updated
  • Proportions Updated
  • Variances
  • Correlations
  • McNemar's test
  • Clustered data New


  • One-way models
  • Two-way models
  • Repeated-measures models

Linear regression New

  • Slope test
  • Coefficient-of-determination test
  • Partial-correlation test

Contingency tables

  • Cochran—Mantel—Haenszel test
  • Matched case—control studies
  • Cochran—Armitage trend test

Cluster randomized designs New

  • One-sample mean
  • Two-sample means
  • One-sample proportion
  • Two-sample proportions
  • Log-rank test

Survival analysis

  • Log-rank test of survival functions Updated
  • Cox proportional hazards model
  • Exponential regression
  • Clustered data New

Solve for

  • Power
  • Sample size
  • Number of clusters New
  • Cluster size New
  • Effect size (minimum detectable effect)

Specify lists of

  • Alpha values
  • Power levels
  • Beta values
  • Sample sizes
  • Ratios of sample sizes
  • And more

Multiple scenarios using

  • All combinations of values
  • Parallel lists of values

Control panel interface

  • Select analysis type from descriptive summaries
  • Specify list of power, sample size, or other levels
  • Automated tables and graphs
  • Customize tables and graphs
  • Command interface too (of course)



  • Automated
  • Customized


  • Automated
  • Customized
  • Simple or comparative

Save results to dataset

Add your own methods

Additional resources

Watch Power and sample size tutorials

See New in Stata 15 for more about what was added in Stata 15.





The Stata Blog: Not Elsewhere Classified Find us on Facebook Follow us on Twitter LinkedIn YouTube Instagram
© Copyright 1996–2019 StataCorp LLC   •   Terms of use   •   Privacy   •   Contact us