Convert Watt per millimetre kelvin to BTU per hour per foot per degree Fahrenheit
Convert Watt per millimetre kelvin (W/(mm·K)) to BTU per hour per foot per degree Fahrenheit (BTU/(h·ft·°F)) instantly and accurately.
Conversion Formula
BTU/(h·ft·°F) = W/(mm·K) × 577.7893165
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).
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).
Quick Reference Table
| Watt per millimetre kelvin (W/(mm·K)) | BTU per hour per foot per degree Fahrenheit (BTU/(h·ft·°F)) |
|---|---|
| 1 W/(mm·K) | 577.789 BTU/(h·ft·°F) |
| 2 W/(mm·K) | 1155.58 BTU/(h·ft·°F) |
| 5 W/(mm·K) | 2888.95 BTU/(h·ft·°F) |
| 10 W/(mm·K) | 5777.89 BTU/(h·ft·°F) |
| 25 W/(mm·K) | 14444.7 BTU/(h·ft·°F) |
| 50 W/(mm·K) | 28889.5 BTU/(h·ft·°F) |
| 100 W/(mm·K) | 57778.9 BTU/(h·ft·°F) |