Heat Sink Size Calculator

This heat sink size calculator will calculate the heat sink width and number fins required to maintain a specified heat source temperature for a heat sink cooled via natural convection and radiation. The heat source is assumed to cover the entire base of the heat sink.

The heat sink size calculator first calculates the optimum spacing between the fins to achieve maximum convection cooling. The width of the heat sink is then calculated based on the number of fins required to dissipate the heat from the heat sink. Reference the blog post, Sizing heat sinks with a few simple equations for details regarding the calculation methodology.

Note: This calculator should not be used in instances where the heat source is much smaller than the base of the heat sink. Concentration of the heat source over an area much smaller than heat sink base is not taken into account in this calculator. Check out the HeatSinkCalculator if you need to evaluate these smaller heat sources.

T_amb: °C 

T_s (max): °C 

P: Watts 

L: mm

H: mm

b: mm

t: mm

Emissivity: 

Calculate

W:

-

mm

s:

-

mm

Number of fins:

-

These results assume the heat source covers the whole base. Real components are usually much smaller, and the heat spreading through the base can raise their temperature well above this estimate.

The full HeatSinkCalculator also compares fan and liquid cooling, and can find the lightest heat sink that meets your temperature limit.

Check your real source temperature