Insulation R-Value Calculator

Calculation Type

Assembly Components

R-Value Guide

Understanding insulation effectiveness by material.

  • Fiberglass R-3.1 to R-3.4 per inch
  • Cellulose R-3.5 to R-3.7 per inch
  • Spray Foam R-6.0 to R-7.0 per inch
  • Rigid Foam R-4.0 to R-6.5 per inch

Code Requirements

Walls

R-13 to R-23

Attic

R-30 to R-60

Floor

R-13 to R-30

Crawl Space

R-10 to R-19

Installation Tips

  • Vapor Barrier Face toward living space
  • Air Gaps Avoid compression
  • Ventilation Maintain proper airflow
  • Moisture Control condensation