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

Convert Watt per metre kelvin (W/(m·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/(m·K) × 6.933471799

About Watt per metre kelvin

The watt per metre kelvin (W/(m·K)) is the SI unit for thermal conductivity defined by Fourier's law q = -λ∇T. Materials span orders of magnitude: aerogels ≈0.015, glass ≈1.0, stainless steel ≈16, aluminium ≈205, copper ≈385, diamond ≈2200 W/(m·K). Referenced in ISO 22007, EN 12667, and all major international standards. 1 W/(m·K) = 1 W/(m·°C).

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).

Quick Reference Table

→ Full Thermal Conductivity Converter