Popular conversions
1 pairsWatt per Meter-Kelvin ↔ BTU per Hour-Foot-°F
W/m·K ↔ Btu/h·ft·°F
Unit guides
2 unitsDetailed guide to this category
Thermal conductivity measures how well a material conducts heat.
Watt per meter-Kelvin is the SI derived unit, widely used in material science and building insulation ratings.
- Physical quantity
- Thermal conductivity
- SI unit
- Watt per meter-Kelvin
- Typical use
- Insulation and heat transfer engineering
What is thermal conductivity?
Thermal conductivity describes a material's ability to conduct heat, derived from Fourier's law of heat conduction.
It is used to compare insulation materials and calculate building heat loss.
Interpreting thermal conductivity
A lower thermal-conductivity value generally means a material transfers heat less readily, which is why low-conductivity materials are used for insulation. A higher value is useful where heat must move efficiently, such as heat exchangers and cookware.
Published values can vary with temperature, moisture, density, direction within the material and test method. Compare specifications measured under similar conditions.
SI and imperial conductivity units
Watt per meter-Kelvin, written W/(m·K), is the common SI-form unit. BTU per hour-foot-degree Fahrenheit is still found in North American building and HVAC material specifications.
The temperature interval in the denominator is part of the unit. Convert the complete conductivity unit rather than only the watt or BTU component.
Unit comparison table
| Unit | Symbol | SI equivalent | System | Common use |
|---|---|---|---|---|
| Watt per Meter-Kelvin | W/(m·K) | SI reference unit | SI | Material science and building specifications |
| BTU per Hour-Foot-°F | Btu/(h·ft·°F) | ≈ 1.730735 W/(m·K) | US customary | North American insulation and HVAC data |
Units
| Unit | Symbol | Information |
|---|---|---|
| Watt per Meter-Kelvin | W/m·K | View unit guide |
| BTU per Hour-Foot-°F | Btu/h·ft·°F | View unit guide |