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Heat Flux Density Converter

Convert heat flux density: W/m², BTU/(h·ft²).

5 units
6 decimals

1 W/m² = 0.316998 BTU/(h·ft²)

About the heat flux density converter

Convert heat flux density between W/m² (SI), kW/m², cal/(s·cm²), and BTU/(h·ft²). Heat flux density is the rate of heat flow per unit area — critical for evaluating insulation, solar irradiance (the solar constant is ~1,361 W/m²), and electronic cooling.

Frequently asked questions

  • How many W/m² is 1 BTU/(h·ft²)?

    One BTU per hour per square foot equals approximately 3.155 W/m².

  • What is the solar constant?

    Approximately 1,361 W/m² — the solar irradiance at the top of Earth’s atmosphere on a surface perpendicular to the Sun.

  • What is the SI unit of heat flux density?

    The watt per square meter (W/m²).

Complete list of heat flux density units