Convert Watt per millimetre kelvin to BTU inch per hour per square foot per degree Fahrenheit

Convert Watt per millimetre kelvin (W/(mm·K)) to BTU inch per hour per square foot per degree Fahrenheit (BTU·in/(h·ft²·°F)) instantly and accurately.

Conversion Formula

BTU·in/(h·ft²·°F) = W/(mm·K) × 6933.471799

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 inch per hour per square foot per degree Fahrenheit

The BTU·in/(h·ft²·°F) equals (1055.05585262 × 0.0254 × 9)/(3600 × 0.09290304 × 5) W/(m·K) ≈0.1442 W/(m·K). The standard US k-factor unit for insulation per ASTM C177, C335, and C518. Mineral wool ≈0.25; expanded polystyrene ≈0.24; polyurethane foam ≈0.14 BTU·in/(h·ft²·°F). 1 BTU·in/(h·ft²·°F) ≈0.1442 W/(m·K).

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