How to get R-Squared after doing stepwise model selection in regression in R I am using R commander to do stepwise model selection in a linear model. When I run stepwise model selection, it reduces some variables, and finally, a model with AIC is provided. However, it does not show the R-squared. I am wondering how I can determine the new value of R-squared? Moreover, is it possible to do stepwise model selection based on adjusted R-squared, not AIC nor BIC?

I'm not familiar with R commander but I assume you can re-fit the final model to get various statistics including R-squared.  Selecting on AIC is very similar to adjusted R-Square but includes a bias correction so I would stick with it.  The most important part however is that selecting a model based on stepwise regression is a bad idea.
https://stats.stackexchange.com/a/20856/2310
