R-value is the industry standard for measuring the insulation’s resistance of heat/cool air flow traveling through it. The higher the R-Value of your insulation, the greater the resistance, however that is only one factor that determines the effectiveness of insulation, and only one aspect you should look at when making your decision on which insulation is best for your home. You can find the R-value of your insulation on the label. The total R-value of your attic is the product of the R-value and the square foot of your crawl space. Batt insulation and blown-in insulation both have varying R-values depending on the material.