Convert Watt per square millimetre to International table BTU per second per square foot
Convert Watt per square millimetre (W/mm²) to International table BTU per second per square foot (BTU(IT)/(s·ft²)) instantly and accurately.
Conversion Formula
BTU(IT)/(s·ft²) = W/mm² × 88.05509184
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.
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.
Quick Reference Table
| Watt per square millimetre (W/mm²) | International table BTU per second per square foot (BTU(IT)/(s·ft²)) |
|---|---|
| 1 W/mm² | 88.0551 BTU(IT)/(s·ft²) |
| 2 W/mm² | 176.11 BTU(IT)/(s·ft²) |
| 5 W/mm² | 440.275 BTU(IT)/(s·ft²) |
| 10 W/mm² | 880.551 BTU(IT)/(s·ft²) |
| 25 W/mm² | 2201.38 BTU(IT)/(s·ft²) |
| 50 W/mm² | 4402.75 BTU(IT)/(s·ft²) |
| 100 W/mm² | 8805.51 BTU(IT)/(s·ft²) |