∘C/W^{\circ}\text{C/W}

Celsius degree per watt

Thermal resistanceexact by definition

The Celsius degree per watt is exactly equal to the kelvin per watt, and it is the form printed on every semiconductor and heatsink datasheet. A TO-220 package is about 62 °C/W junction to ambient in free air and 1 °C/W junction to case; the heatsink and interface make up the rest.

Watch out: Datasheet θJA figures are measured on a specified board in still air and are close to useless as an absolute prediction. Treat them as a comparison between parts, not as a design number.

1 ∘C/W^{\circ}\text{C/W} 1 K/W\text{K/W}

One celsius degree per watt in every thermal resistance unit

1,000Celsius degree per kilowatt (°C/kW)
1,000kelvin per kilowatt (K/kW)
1.16222Celsius hour per kilocalorie (°C·h/kcal)
1kelvin per watt (K/W)
1Celsius degree per watt (°C/W)this unit
0.527528Fahrenheit hour per BTU (°F·h/BTU)
0.527528Rankine hour per BTU (°R·h/BTU)
0.001kelvin per milliwatt (K/mW)