We went straight to Energy Star for this answer!  They are experts in this area and have curated up-to-date information on this.  Their information relates to all parts of the U.S., so wherever you live, you can get an accurate read on what R-Value your insulation is recommended to be at.

First what is an R-Value:

R-Value measures insulation’s ability to resist heat that would be traveling through it.  Different climates would require different levels of insulation for it to be cost effective for the homeowner.

Check here  to determine the correct levels of insulation you need, and what R-Values are recommended where you live!