Figuring out the right insulation size for your home can be a challenging task. But with the right measurements and knowledge of insulation types, you can easily determine what type of insulation you need. To start, measure the height and length of each wall in your room. Note the space between the posts and multiply the length of the wall by the height of the wall to determine what type of home insulation is required.
Depending on where you live and the part of the house you are insulating (walls, mezzanine, attic, etc.), typical recommendations for exterior walls are those of R-13 to R-23, while those of R-30, R-38 and R-49 are common for roofs and attics. The Department of Energy (DOE) provides ranges for recommended insulation levels. When taking measurements, make sure to measure everything in inches, length x width. Then convert all your measurements from square inches to square feet by dividing the number of square inches by 144. You'll likely need a measuring tape, a calculator, and possibly a stool or ladder.