All Calculators
Heat Sink Sizing Calculator
Calculate the required thermal resistance for your heat sink based on device specifications.
Input Parameters
W
Total power to be dissipated by the device
°C
From device datasheet (typically 125-175°C)
°C
Operating environment temperature
°C/W
From device datasheet (Rth_jc)
°C/W
Thermal paste/pad resistance (typically 0.1-0.5°C/W)
Results
warning
Very low thermal resistance required. Consider high-performance heat sinks with forced convection.
Required Heat Sink Thermal Resistance
0.15°C/W
Thermal Margin
0.0°C
Temp Rise Budget
85°C
Formula Used
Rth_hs = (Tj_max - Ta) / P - Rth_jc - Rth_intThis calculation determines the maximum thermal resistance your heat sink can have while keeping the junction temperature below the specified limit.