Convert BTU per hour per foot per degree Fahrenheit to Watt per millimetre kelvin
Convert BTU per hour per foot per degree Fahrenheit (BTU/(h·ft·°F)) to Watt per millimetre kelvin (W/(mm·K)) instantly and accurately.
Conversion Formula
W/(mm·K) = BTU/(h·ft·°F) × 0.001730734666
About BTU per hour per foot per degree Fahrenheit
The BTU/(h·ft·°F) equals (1055.05585262 × 9)/(3600 × 0.3048 × 5) W/(m·K) ≈1.7307 W/(m·K). Standard US thermal conductivity unit in ASHRAE Handbook and ASTM C1045. Copper: ≈223; carbon steel: ≈26; brick: ≈0.44; glass fibre insulation: ≈0.025 BTU/(h·ft·°F). 1 BTU/(h·ft·°F) = 12 BTU·in/(h·ft²·°F) ≈1.7307 W/(m·K).
About Watt per millimetre kelvin
The watt per millimetre kelvin (W/(mm·K)) equals exactly 1000 W/(m·K) since 1 mm = 10⁻³ m. Used in microelectronics thermal engineering where components are millimetre-scale: copper ≈0.385, silicon ≈0.148 W/(mm·K). Thermal interface material datasheets for high-performance pads and solder joints commonly use this unit. 1 W/(mm·K) = 1000 W/(m·K) = 10 W/(cm·K).
Quick Reference Table
| BTU per hour per foot per degree Fahrenheit (BTU/(h·ft·°F)) | Watt per millimetre kelvin (W/(mm·K)) |
|---|---|
| 1 BTU/(h·ft·°F) | 0.00173073 W/(mm·K) |
| 2 BTU/(h·ft·°F) | 0.00346147 W/(mm·K) |
| 5 BTU/(h·ft·°F) | 0.00865367 W/(mm·K) |
| 10 BTU/(h·ft·°F) | 0.0173073 W/(mm·K) |
| 25 BTU/(h·ft·°F) | 0.0432684 W/(mm·K) |
| 50 BTU/(h·ft·°F) | 0.0865367 W/(mm·K) |
| 100 BTU/(h·ft·°F) | 0.173073 W/(mm·K) |