Watt per Metre Kelvin (W/(m·K))
The watt per metre kelvin is the SI unit of thermal conductivity (k or λ): the heat flow through 1 m² of a 1 m thick layer for each kelvin of temperature difference. Copper is about 400 W/(m·K), mineral wool about 0.035.
Symbol: W/(m·K) (ASCII: W/(m*K))
Quantity: thermal conductivity (k, λ)
SI relation: W/(m·K) is the coherent SI unit of thermal conductivity.
Derivation: The SI unit of thermal conductivity: heat flow (W) per metre of thickness per kelvin of temperature difference
Exact: yes, by definition
Typical uses
- Insulation λ-values (EN 12667, ISO 8301)
- Heat exchanger and heat sink design
- Material datasheets for metals, polymers and ceramics
Convert watts per metre kelvin to other units
| Conversion | 1 W/(m·K) equals | Reverse |
|---|---|---|
| watt per metre kelvin to BTU per hour foot degree Fahrenheit | 0.5777893165 BTU/(h·ft·°F) | BTU per hour foot degree Fahrenheit to watt per metre kelvin |
| watt per metre kelvin to BTU inch per hour square foot degree Fahrenheit | 6.933471799 BTU·in/(h·ft²·°F) | BTU inch per hour square foot degree Fahrenheit to watt per metre kelvin |
| watt per metre kelvin to milliwatt per metre kelvin | 1000 mW/(m·K) | milliwatt per metre kelvin to watt per metre kelvin |
| watt per metre kelvin to kilocalorie per hour metre degree Celsius | 0.8598452279 kcal/(h·m·°C) | kilocalorie per hour metre degree Celsius to watt per metre kelvin |
| watt per metre kelvin to watt per centimetre kelvin | 0.01 W/(cm·K) | watt per centimetre kelvin to watt per metre kelvin |
| watt per metre kelvin to calorie per second centimetre degree Celsius | 0.002390057361 cal/(s·cm·°C) | calorie per second centimetre degree Celsius to watt per metre kelvin |
Open the Thermal Conductivity Converter to convert any value between all units.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4, coherent derived units with special names.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Watt per Metre Kelvin (W/(m·K)). Retrieved October 25, 2026, from https://scientificconverters.com/units/watt-per-meter-kelvin/
IEEE
Scientific Converters, "Watt per Metre Kelvin (W/(m·K))," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/units/watt-per-meter-kelvin/