U-Value & Heat Loss

Calculate the U-value of a layered wall and the heat lost through it.

Layer 1 Thickness (mm)

Layer 1 Conductivity (W/m·K)

Layer 2 Thickness (mm)

Layer 2 Conductivity (W/m·K)

Layer 3 Thickness (mm)

Layer 3 Conductivity (W/m·K)

Area (m²)

Temperature Difference (°C)

About this calculator

Adds the thermal resistance of up to three layers (thickness ÷ conductivity) plus standard surface resistances, gives U = 1 ÷ R, and the heat loss Q = U·A·ΔT.