Thermal Conductivity Converter
Convert thermal conductivity between W/(m·K), W/(cm·K), BTU/(h·ft·°F), BTU·in/(h·ft²·°F), kcal/(h·m·°C) and cal/(s·cm·°C).
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Thermal Conductivity units
Every unit below converts to every other one in the calculator. Values are relative to the base unit, the watt per meter kelvin (W/(m·K)).
| Unit | Symbol | System | Value |
|---|---|---|---|
| Watt per meter kelvin | W/(m·K) | SI | Base unit |
| Watt per centimeter kelvin | W/(cm·K) | SI | = 100 W/(m·K) |
| BTU per hour foot degree Fahrenheit | BTU/(h·ft·°F) | US customary | ≈ 1.730734666 W/(m·K) |
| BTU inch per hour square foot degree Fahrenheit | BTU·in/(h·ft²·°F) | US customary | ≈ 0.1442278889 W/(m·K) |
| Kilocalorie (IT) per hour meter degree Celsius | kcal/(h·m·°C) | metric | = 1.163 W/(m·K) |
| Calorie (thermochemical) per second centimeter degree Celsius | cal/(s·cm·°C) | CGS | = 418.4 W/(m·K) |
Watt per meter kelvin quick reference
| Watt per meter kelvin | BTU per hour foot degree Fahrenheit | BTU inch per hour square foot degree Fahrenheit |
|---|---|---|
| 1 W/(m·K) | ≈ 0.5777893165 BTU/(h·ft·°F) | ≈ 6.933471799 BTU·in/(h·ft²·°F) |
| 10 W/(m·K) | ≈ 5.777893165 BTU/(h·ft·°F) | ≈ 69.33471799 BTU·in/(h·ft²·°F) |
| 100 W/(m·K) | ≈ 57.77893165 BTU/(h·ft·°F) | ≈ 693.3471799 BTU·in/(h·ft²·°F) |
| 1000 W/(m·K) | ≈ 577.7893165 BTU/(h·ft·°F) | ≈ 6933.471799 BTU·in/(h·ft²·°F) |
Among the 6 thermal conductivity units on this page, the smallest is the btu inch per hour square foot degree fahrenheit (BTU·in/(h·ft²·°F)) and the largest is the calorie (thermochemical) per second centimeter degree celsius (cal/(s·cm·°C)).
More thermal conductivity conversions
- Watt per meter kelvin to BTU per hour foot degree FahrenheitW/(m·K) → BTU/(h·ft·°F)
- BTU per hour foot degree Fahrenheit to Watt per meter kelvinBTU/(h·ft·°F) → W/(m·K)
- Watt per meter kelvin to BTU inch per hour square foot degree FahrenheitW/(m·K) → BTU·in/(h·ft²·°F)
- BTU inch per hour square foot degree Fahrenheit to Watt per meter kelvinBTU·in/(h·ft²·°F) → W/(m·K)
About thermal conductivity units
Thermal conductivity (k or λ) is a material property: the heat that flows through a 1 m thick layer, per square meter, for each kelvin of temperature difference. Its SI unit is the watt per meter kelvin, W/(m·K). Copper is roughly 400 W/(m·K), while building insulation is about 0.03 to 0.04 W/(m·K).
One BTU/(h·ft·°F) is about 1.7307 W/(m·K). US insulation data often uses the "k-value" in BTU·in/(h·ft²·°F), about 0.14423 W/(m·K). Older metric units use the IT kilocalorie, kcal/(h·m·°C), exactly 1.163 W/(m·K), or the thermochemical calorie, cal/(s·cm·°C), exactly 418.4 W/(m·K).
Frequently asked questions
- How do I convert BTU/(h·ft·°F) to W/(m·K)?
- Multiply by about 1.73073. In the other direction, 1 W/(m·K) is about 0.57779 BTU/(h·ft·°F).
- What is the k-value of insulation?
- Its thermal conductivity in BTU·in/(h·ft²·°F). One such unit is about 0.144228 W/(m·K), and 1 W/(m·K) is about 6.9335. The US R-value per inch of thickness is 1 ÷ k.
- How many BTUs per hour foot degree Fahrenheit are in one watt per meter kelvin?
- One watt per meter kelvin ≈ 0.5777893165 BTU/(h·ft·°F) (BTUs per hour foot degree Fahrenheit).
- How many BTU inches per hour square foot degree Fahrenheit are in one watt per meter kelvin?
- One watt per meter kelvin ≈ 6.933471799 BTU·in/(h·ft²·°F) (BTU inches per hour square foot degree Fahrenheit).