Convert International table BTU per hour per square foot to Watt per square metre
Convert International table BTU per hour per square foot (BTU(IT)/(h·ft²)) to Watt per square metre (W/m²) instantly and accurately.
Conversion Formula
W/m² = BTU(IT)/(h·ft²) × 3.154590745
About International table BTU per hour per square foot
The international table BTU per hour per square foot (BTU(IT)/(h·ft²)) equals 1055.05585262/(3600×0.09290304) ≈ 3.15459 W/m². The standard US heat flux unit in ASHRAE, ASTM, and building codes for thermal resistance (R-value), boiler ratings, and heat exchanger design. 1 BTU(IT)/(h·ft²) ≈ 3.15459 W/m².
About Watt per square metre
The watt per square metre (W/m²) is the SI coherent unit for heat flux density and irradiance. Solar irradiance at Earth's surface ≈ 1000 W/m²; solar constant ≈ 1361 W/m²; human skin radiative emission ≈ 100 W/m²; global average geothermal flux ≈ 0.087 W/m². Referenced in ISO 80000-4. 1 W/m² = 1 J/(s·m²) = 10⁻³ kW/m².
Quick Reference Table
| International table BTU per hour per square foot (BTU(IT)/(h·ft²)) | Watt per square metre (W/m²) |
|---|---|
| 1 BTU(IT)/(h·ft²) | 3.15459 W/m² |
| 2 BTU(IT)/(h·ft²) | 6.30918 W/m² |
| 5 BTU(IT)/(h·ft²) | 15.773 W/m² |
| 10 BTU(IT)/(h·ft²) | 31.5459 W/m² |
| 25 BTU(IT)/(h·ft²) | 78.8648 W/m² |
| 50 BTU(IT)/(h·ft²) | 157.73 W/m² |
| 100 BTU(IT)/(h·ft²) | 315.459 W/m² |