Fourier Heat Conduction Calculator

About this calculator

Fourier's law of heat conduction states that steady-state heat flow through a material is Q = k·A·ΔT / L, where k is the thermal conductivity of the material (in W/m·K), A is the cross-sectional area, ΔT is the temperature difference across it, and L is the thickness. Higher conductivity — copper at roughly 400 W/m·K versus fiberglass insulation at around 0.04 — means far more heat escapes for the same temperature gradient.

Mechanical and building-envelope engineers use this exact relationship to size insulation thickness for walls and pipes, estimate heat loss through a wall or window, and check that a heat sink can shed enough wattage in electronics cooling.