Thermal Conductivity Converter

What Is Thermal Conductivity

Thermal conductivity measures how well a material conducts heat. You express this property in watts per meter per kelvin (W/(m·K)) in SI units. High thermal conductivity materials like copper transfer heat quickly. Low thermal conductivity materials like foam insulate effectively.

Building designers use thermal conductivity to select insulation materials. You calculate heat loss through walls and roofs using these values. Electronics engineers choose heat sink materials based on thermal conductivity for efficient cooling.

Fourier Law of Heat Conduction

Calculate heat transfer rate using Fourier law:

Where Q equals heat transfer rate in watts, k equals thermal conductivity, A equals cross-sectional area in square meters, ΔT equals temperature difference in kelvin, and d equals material thickness in meters.

Example: A copper plate (k = 401 W/(m·K)) with area 0.5 m² and thickness 0.01 m has a 50°C temperature difference. The heat transfer equals:

Thermal Conductivity of Common Materials

R-Value and Thermal Resistance

R-value measures thermal resistance in building insulation. You calculate R-value from thermal conductivity using this formula:

Where R equals thermal resistance in m²·K/W, d equals material thickness in meters, and k equals thermal conductivity in W/(m·K).

Example: A 0.1 m thick fiberglass insulation (k = 0.04 W/(m·K)) gives you:

Convert to imperial R-value by multiplying by 5.678. The example above equals R-14.2 in imperial units.

Unit Conversion Factors

Frequently Asked Questions