Heat Flux Density Converter

Convert between all heat flux density units instantly. Select your units from the dropdowns below and enter a value to see the conversion in real-time.

SI unit: watt per square metre (W/m²)

Conversion Formula

About Heat Flux Density Units

Common Heat Flux Density Conversions

• 1 W/m² = 1 J/(s·m²) (exact); solar constant ≈ 1361 W/m²; Earth surface irradiance ≈ 1000 W/m²
• 1 kW/m² = 1000 W/m² = 0.1 W/cm² (exact); 1 mW/cm² = 10 W/m² (exact)
• 1 BTU(IT)/(h·ft²) ≈ 3.15459 W/m²; 1 W/m² ≈ 0.31700 BTU(IT)/(h·ft²)
• 1 kcal(th)/(h·m²) = 4184/3600 ≈ 1.1622 W/m² (exact: 1 kcal(th) = 4184 J)
• 1 W/cm² = 10⁴ W/m² = 10 kW/m² (exact; 1 cm² = 10^-4 m²)
• 1 cal(th)/(s·cm²) = 41840 W/m² (exact: 1 cal(th) = 4.184 J; 1 cm² = 10^-4 m²)
• 1 erg/(s·cm²) = 10^-3 W/m² = 1 mW/m² (exact: 1 erg = 10^-7 J; CGS irradiance unit)
• 1 W/mm² = MW/m² = 10⁶ W/m² (exact); used in high-power laser and fusion engineering

Direct Converters