Convert BTU inch per hour per square foot per degree Fahrenheit to Milliwatt per metre degree Celsius
Convert BTU inch per hour per square foot per degree Fahrenheit (BTU·in/(h·ft²·°F)) to Milliwatt per metre degree Celsius (mW/(m·°C)) instantly and accurately.
Conversion Formula
mW/(m·°C) = BTU·in/(h·ft²·°F) × 144.2278889
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).
About Milliwatt per metre degree Celsius
The milliwatt per metre degree Celsius (mW/(m·°C)) equals exactly 1 mW/(m·K) = 10⁻³ W/(m·K) since temperature intervals 1 °C = 1 K. Used interchangeably with mW/(m·K) in building physics, insulation standards (EN ISO 10456), and material datasheets where Celsius is the preferred temperature scale. Still air ≈26 mW/(m·°C); mineral wool ≈35 mW/(m·°C). 1 mW/(m·°C) = 1 mW/(m·K) = 10⁻³ W/(m·K).
Quick Reference Table
| BTU inch per hour per square foot per degree Fahrenheit (BTU·in/(h·ft²·°F)) | Milliwatt per metre degree Celsius (mW/(m·°C)) |
|---|---|
| 1 BTU·in/(h·ft²·°F) | 144.228 mW/(m·°C) |
| 2 BTU·in/(h·ft²·°F) | 288.456 mW/(m·°C) |
| 5 BTU·in/(h·ft²·°F) | 721.139 mW/(m·°C) |
| 10 BTU·in/(h·ft²·°F) | 1442.28 mW/(m·°C) |
| 25 BTU·in/(h·ft²·°F) | 3605.7 mW/(m·°C) |
| 50 BTU·in/(h·ft²·°F) | 7211.39 mW/(m·°C) |
| 100 BTU·in/(h·ft²·°F) | 14422.8 mW/(m·°C) |