Convert BTU per second per foot per degree Fahrenheit to Watt per millimetre kelvin
Convert BTU per second per foot per degree Fahrenheit (BTU/(s·ft·°F)) to Watt per millimetre kelvin (W/(mm·K)) instantly and accurately.
Conversion Formula
W/(mm·K) = BTU/(s·ft·°F) × 6.230644799
About BTU per second per foot per degree Fahrenheit
The BTU per second per foot per degree Fahrenheit (BTU/(s·ft·°F)) equals (1055.05585262 × 9)/(0.3048 × 5) W/(m·K) ≈6230.6 W/(m·K). Equal to 3600 × BTU/(h·ft·°F). Reserved for extremely high-power transient applications in US engineering literature; copper ≈0.0617; carbon steel ≈0.0072 BTU/(s·ft·°F). 1 BTU/(s·ft·°F) = 3600 BTU/(h·ft·°F) ≈6230.6 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 second per foot per degree Fahrenheit (BTU/(s·ft·°F)) | Watt per millimetre kelvin (W/(mm·K)) |
|---|---|
| 1 BTU/(s·ft·°F) | 6.23064 W/(mm·K) |
| 2 BTU/(s·ft·°F) | 12.4613 W/(mm·K) |
| 5 BTU/(s·ft·°F) | 31.1532 W/(mm·K) |
| 10 BTU/(s·ft·°F) | 62.3064 W/(mm·K) |
| 25 BTU/(s·ft·°F) | 155.766 W/(mm·K) |
| 50 BTU/(s·ft·°F) | 311.532 W/(mm·K) |
| 100 BTU/(s·ft·°F) | 623.064 W/(mm·K) |