Everyday Scientist

visual sample size calculator

March 3, 2026 at 4:55 pm | sam | tutorial

The goal of this Shiny app is to help use our intuitions about how our graphs typically look to estimate the effect size, and thus the required sample size.

It’s embedded below, but better viewed here:
https://samjlord.shinyapps.io/visualsamplesizecalculator

Warning: this is still in beta, and I need to confirm that all the calculations are indeed correct.

Please give me any feedback to make this more useful!