Heat Conduction Calculator

This calculator works out the rate of heat conduction through a material using Fourier's law, the fundamental relationship governing how heat flows through solids. Conduction is the transfer of heat through a material without the material itself moving, as warmth spreads from the hot side to the cold side of a wall, a window or a pot. How fast it flows depends on four things: the thermal conductivity of the material, a measure of how readily it carries heat, the area through which the heat passes, the temperature difference driving the flow, and the thickness the heat must cross. Fourier's law ties these together, and it is central to insulation, building design, cookware, electronics cooling and any situation where keeping heat in or out matters. This tool computes it. You enter the thermal conductivity, the area, the temperature difference between the two sides, and the thickness of the material, and the calculator returns the rate of heat flow in watts, along with the R-value, a measure of insulating resistance, the heat flux per square metre, and the energy lost over a day. The results update as you type, so you can see how thicker or better-insulating materials cut the heat flow. Use it for insulation and building calculations, for thermal engineering, for cookware and electronics, or for physics study. The relationship is intuitive once seen: heat flow rises with conductivity, area and temperature difference, and falls with thickness, so a thick layer of a poorly conducting material, exactly what insulation is, dramatically slows heat loss. The R-value, the thickness divided by the conductivity, is the figure used to rate insulation: a higher R-value means better resistance to heat flow, which is why thicker, less conductive insulation earns a higher rating.

Fourier's law: heat rate = conductivity x area x temp difference / thickness. R-value = thickness / conductivity. Higher R-value means better insulation.