R-Value Calculator
Calculate the thermal resistance (R-value) of an insulation material based on thickness and thermal conductivity.
How to Use the R-Value Calculator
- Enter the insulation thickness in inches.
- Select the material type (fiberglass, foam, or cellulose).
- Click Calculate for R-value and performance description.
Casos de Uso
- •Comparing insulation materials.
- •Checking code compliance for new builds.
- •Retrofit insulation planning.
- •Energy audit assessments.
Fórmula
R = thickness (inches) / k-value. Fiberglass k=0.25, Spray foam k=0.17, Cellulose k=0.27.
Preguntas Frecuentes
What is R-value?
R-value measures thermal resistance — how well a material resists heat flow. Higher R = better insulation.
What R-value do I need?
Recommended R-values vary by climate zone. Attics: R-38 to R-60. Walls: R-13 to R-21. Floors: R-19 to R-30.
Can I add R-values together?
Yes — when insulation layers are stacked, their R-values add directly.