What R-value do I actually need for a sleeping pad?

For summer use, an R-value of 2-3 is typically sufficient. Three-season backpacking generally calls for R-4 or higher, and winter or snow camping pushes the recommendation to R-5 or above, with cold-weather specialists often preferring R-6+. Side sleepers tend to lose more heat through compression points, so erring higher is common advice in specialist communities.