Convert thermal conductivity units — W/(m·K), BTU/(h·ft·°F), cal/(s·cm·°C) and more.
| Unit | Name | Value |
|---|---|---|
| W/(m·K) | Watt/(Meter·Kelvin) | 418.68 |
| kW/(m·K) | Kilowatt/(Meter·Kelvin) | 0.41868 |
| BTU/(h·ft·°F) | BTU/(Hour·Foot·°F) | 241.90948 |
| kcal/(h·m·°C) | Kilocalorie/(Hour·m·°C) | 360 |
Formula: kW/(m·K) = cal/(s·cm·K) × 0.4187
Multiply any cal/(s·cm·K) value by 0.4187 to get kW/(m·K).
Reverse: cal/(s·cm·K) = kW/(m·K) × 2.388
Copper reference: 0.9578 cal/(s·cm·K) = 0.401 kW/(m·K)
Factor: 1 cal/(s·cm·K) = 0.4187 kW/(m·K)
| cal/(s·cm·K) (cal/(s·cm·K)) | kW/(m·K) (kW/(m·K)) | Material |
|---|---|---|
| 5.255 cal/(s·cm·K) | 2.2 kW/(m·K) | Diamond |
| 1.025 cal/(s·cm·K) | 0.429 kW/(m·K) | Silver |
| 0.9578 cal/(s·cm·K) | 0.401 kW/(m·K) | Copper |
| 0.7595 cal/(s·cm·K) | 0.318 kW/(m·K) | Gold |
| 0.5661 cal/(s·cm·K) | 0.237 kW/(m·K) | Aluminum |
| 0.1242 cal/(s·cm·K) | 0.052 kW/(m·K) | Cast iron |
| 0.1194 cal/(s·cm·K) | 0.05 kW/(m·K) | Steel (carbon) |
| 0.005971 cal/(s·cm·K) | 0.0025 kW/(m·K) | Marble |
| 0.00406 cal/(s·cm·K) | 0.0017 kW/(m·K) | Concrete |
| 0.002388 cal/(s·cm·K) | 0.001 kW/(m·K) | Glass |
| 0.001433 cal/(s·cm·K) | 0.0006 kW/(m·K) | Water (20°C) |
| 0.000406 cal/(s·cm·K) | 0.00017 kW/(m·K) | Wood (oak) |
| 9.554e-05 cal/(s·cm·K) | 4.000e-05 kW/(m·K) | Fiberglass batt |
| 6.210e-05 cal/(s·cm·K) | 2.600e-05 kW/(m·K) | Air (25°C) |
| 3.583e-05 cal/(s·cm·K) | 1.500e-05 kW/(m·K) | Aerogel |
1 cal/(s·cm·K) = 0.4187 kW/(m·K).
Copper ≈ 401 W/(m·K). Steel ≈ 50 W/(m·K). Glass ≈ 1 W/(m·K). Air ≈ 0.026 W/(m·K).
Multiply result by 2.388 to recover the original cal/(s·cm·K) value.
Specifies insulation and wall assembly thermal conductivity in W/(m·K) for energy compliance calculations.
Uses BTU/(h·ft·°F) for US building code compliance and W/(m·K) for metric heat transfer calculations.
Compares thermal conductivity of metals, polymers, and composites in W/(m·K) for thermal management design.
Selects thermal interface materials and heatsinks using conductivity data in W/(m·K).
Designs heat exchangers using shell and tube thermal conductivity specifications in W/(m·K).
Measures and reports thermal conductivity of novel materials (graphene, CNTs, aerogels) in W/(m·K) or kW/(m·K).
Calorie per second per centimeter per kelvin (cal/(s·cm·K)) is the CGS unit of thermal conductivity, equal to 418.68 W/(m·K). It was the standard in pre-SI physics and chemistry literature.
Cal/(s·cm·K) appears in older scientific handbooks and classic thermodynamics texts. Copper in CGS = 0.923 cal/(s·cm·K); iron = 0.179 cal/(s·cm·K); water = 0.00143 cal/(s·cm·K). The unit is rarely used in modern practice.
Interesting fact: The CGS unit cal/(s·cm·K) is 418.68× larger than W/(m·K) — so most materials have very small values in CGS. Water at 0.00143 cal/(s·cm·K) demonstrates why the CGS unit became impractical for most engineering applications.
Kilowatt per meter per kelvin (kW/(m·K)) equals 1,000 W/(m·K) and is used for highly thermally conductive materials. Diamond at 2.2 kW/(m·K) and silver at 0.429 kW/(m·K) are examples where kW/(m·K) provides convenient values.
kW/(m·K) is used in research papers and data tables for metallic and crystalline materials with very high conductivity. Carbon nanotubes can reach 3–6 kW/(m·K) along their axis — the highest known at room temperature.
Interesting fact: Graphene, a single layer of carbon atoms, has a thermal conductivity of about 4–5 kW/(m·K) in-plane — the highest of any known material. This makes it a promising material for next-generation thermal management in electronics.
Thermal conductivity measures how readily a material conducts heat. The SI unit W/(m·K) is universal in science; US building codes use BTU/(h·ft·°F); older European engineering uses kcal/(h·m·°C); CGS physics uses cal/(s·cm·K). Key anchors: air 0.026 W/(m·K), glass 1.0, steel 50, copper 401, diamond 2,200.
Exact factor: 1 cal/(s·cm·K) = 0.4187 kW/(m·K). Reverse: 1 kW/(m·K) = 2.388 cal/(s·cm·K).
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.