Insulation Calculator – Calculate R-value and Required Thickness for Building Insulation
The insulation calculator determines building insulation thermal resistance (R-value) and U-value based on insulation layer thickness and material lambda values. Perfect for assessing building energy efficiency.
Enter insulation layer thicknesses and materials (mineral wool, EPS, XPS, wood fiber board, etc.), and the calculator will compute total R-value and U-value. Compare results against building code minimum requirements.
What is good insulation for a single-family home?
International building standards typically require exterior walls U-value ≤ 0.17 W/m²K, roof ≤ 0.09 W/m²K, and foundation ≤ 0.16 W/m²K for new construction. Passive house standards demand even lower U-values. For example, 12 inches of mineral wool (λ = 0.036) provides R-value of 8.33 m²K/W and U-value of 0.12 W/m²K.
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Browse all tools →The insulation calculator estimates the amount of insulation material needed and helps compare different insulation options. Useful for builders and renovators wanting to improve home energy efficiency.
Input the dimensions of the area to be insulated and select insulation thickness, and the calculator tells you the required material quantity.
- Calculate insulation material needs in square meters or cubic meters.
- Estimate the effect of insulation thickness on thermal performance (U-value).
- Compare the efficiency and consumption of different insulation materials.
The calculator gives theoretical material consumption – in practice, waste occurs from cutting and fitting.
- Add 5–15% to the result for cutting waste.
- U-value indicates insulation performance – lower value means better insulation.
- Material choice is affected by application, moisture conditions, and fire safety.
Insulation affects the building's moisture engineering and structural function as a whole.
- Incorrect insulation can cause moisture damage – planning is important.
- Building codes set minimum requirements for insulation thickness.
- For larger projects, consult an energy advisor or building designer.