Convert Milliwatt per square metre to International table BTU per hour per square foot

Convert Milliwatt per square metre (mW/m²) to International table BTU per hour per square foot (BTU(IT)/(h·ft²)) instantly and accurately.

Milliwatt per square metre (mW/m²)
International table BTU per hour per square foot (BTU(IT)/(h·ft²))

Conversion Formula

BTU(IT)/(h·ft²) = mW/m² × 0.0003169983306

About Milliwatt per square metre

The milliwatt per square metre (mW/m²) equals 10⁻³ W/m². Relevant in geothermal surveys: global average continental heat flux ≈ 65 mW/m², oceanic ≈ 101 mW/m². Used in building physics for quantifying very small heat leakage through ultra-high-performance insulation. 1 mW/m² = 10⁻³ W/m² = 1 erg/(s·cm²).

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.

Quick Reference Table

Milliwatt per square metre (mW/m²)International table BTU per hour per square foot (BTU(IT)/(h·ft²))
1 mW/m²0.000316998 BTU(IT)/(h·ft²)
2 mW/m²0.000633997 BTU(IT)/(h·ft²)
5 mW/m²0.00158499 BTU(IT)/(h·ft²)
10 mW/m²0.00316998 BTU(IT)/(h·ft²)
25 mW/m²0.00792496 BTU(IT)/(h·ft²)
50 mW/m²0.0158499 BTU(IT)/(h·ft²)
100 mW/m²0.0316998 BTU(IT)/(h·ft²)

→ Full Heat Flux Density Converter