Convert International table BTU per second per square foot to Watt per square millimetre
Convert International table BTU per second per square foot (BTU(IT)/(s·ft²)) to Watt per square millimetre (W/mm²) instantly and accurately.
Conversion Formula
W/mm² = BTU(IT)/(s·ft²) × 0.01135652668
About International table BTU per second per square foot
The international table BTU per second per square foot (BTU(IT)/(s·ft²)) equals 1055.05585262/0.09290304 ≈ 11357 W/m² (= 3600 × BTU(IT)/(h·ft²)). Used for extreme heat flux: atmospheric re-entry aerodynamic heating, solid rocket nozzle throat, and nuclear reactor thermal hydraulics design. 1 BTU(IT)/(s·ft²) ≈ 11357 W/m².
About Watt per square millimetre
The watt per square millimetre (W/mm²) equals exactly 10⁶ W/m². Used in high-power laser material processing - cutting, welding, and additive manufacturing - and electron beam applications. A 1 kW laser focused to 1 mm² achieves 1 W/mm². Numerically equal to MW/m². 1 W/mm² = 10⁶ W/m² = 100 W/cm².
Quick Reference Table
| International table BTU per second per square foot (BTU(IT)/(s·ft²)) | Watt per square millimetre (W/mm²) |
|---|---|
| 1 BTU(IT)/(s·ft²) | 0.0113565 W/mm² |
| 2 BTU(IT)/(s·ft²) | 0.0227131 W/mm² |
| 5 BTU(IT)/(s·ft²) | 0.0567826 W/mm² |
| 10 BTU(IT)/(s·ft²) | 0.113565 W/mm² |
| 25 BTU(IT)/(s·ft²) | 0.283913 W/mm² |
| 50 BTU(IT)/(s·ft²) | 0.567826 W/mm² |
| 100 BTU(IT)/(s·ft²) | 1.13565 W/mm² |