Flat Plate Heat Sink Calculator

Use this free online calculator to estimate the performance of a flat plate used as heat sink for LEDs, MOSFETs, diodes or other electronic or electrical devices. This calculator uses the calculation methodology explained in the blog posts, How to design a flat plate heat sink and Performance of a LED flat plate heat sink in multiple orientations.

The heat sink thermal resistance and temperature of the heat source are calculated by the calculator.

Air Flow
Power Source




Predefined materials:
Thermal conductivity:

Do you need more functionality?

The HeatSinkCalculator offers online heat sink analysis software that allows you to analyze plate fins heat sinks cooled via radiation, and natural or forced convection. Multiple heat sources attached to the heat sink can be evaluated. In addition the calculator automatically determines the optimal dimensions of your heat sink to achieve the lowest heat source temperature. Click below to learn more.