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Heat Flux Density Converter

Convert between W/m², BTU/(h·ft²), BTU/(h·in²), cal/(s·cm²) and other heat flux density units.

Universal Heat Flux Density Converter

About heat flux density conversions

Heat flux density conversions are used in thermal engineering, meteorology, building science, and solar energy. Our converter covers watts per square meter and BTU per hour-square inch. Heat flux density measures the rate of heat energy transfer through a unit area. Whether you are analyzing insulation, solar irradiance, or electronic cooling, this converter provides accurate conversions.

Most popular heat flux density conversions

Available units

Watt per Square Meter (W/m²)Kilowatt per Square Meter (kW/m²)Milliwatt per Square Meter (mW/m²)Watt per Square Centimeter (W/cm²)Watt per Square Inch (W/in²)BTU per Hour Square Foot (BTU/(h·ft²))BTU per Hour Square Inch (BTU/(h·in²))BTU per Second Square Foot (BTU/(s·ft²))BTU per Minute Square Foot (BTU/(min·ft²))Calorie per Second Square Centimeter (cal/(s·cm²))Kilocalorie per Hour Square Meter (kcal/(h·m²))Erg per Second Square Centimeter (erg/(s·cm²))Horsepower per Square Foot (hp/ft²)

Popular heat flux density conversions (156 total)

Unit definitions

Watt per Square Meter (W/m²)

Solar constant ≈ 1361 W/m².

Origin: Solar radiation standard.

Current use: Solar energy, Climate, Meteorology

Kilowatt per Square Meter (kW/m²)

1000 W/m².

Origin: HVAC, solar engineering.

Current use: Solar energy, HVAC, Heat transfer

Milliwatt per Square Meter (mW/m²)

0.001 W/m².

Origin: Low-level heat flux measurement.

Current use: Building physics, Insulation testing

Watt per Square Centimeter (W/cm²)

10000 W/m².

Origin: High-intensity heat flux.

Current use: Laser heating, Industrial processes

Watt per Square Inch (W/in²)

1550 W/m².

Origin: US engineering.

Current use: Electronics cooling, US standards

BTU per Hour Square Foot (BTU/(h·ft²))

3.15459 W/m².

Origin: US building industry.

Current use: HVAC, Building design, US standards

BTU per Hour Square Inch (BTU/(h·in²))

454.26 W/m².

Origin: US engineering.

Current use: High-intensity heating, Industrial, US

BTU per Second Square Foot (BTU/(s·ft²))

11356.53 W/m².

Origin: High-flux thermal analysis.

Current use: Combustion, Furnace design

BTU per Minute Square Foot (BTU/(min·ft²))

189.28 W/m².

Origin: Thermal process engineering.

Current use: Oven design, Industrial heating

Calorie per Second Square Centimeter (cal/(s·cm²))

41868 W/m².

Origin: CGS thermodynamics.

Current use: Physics research, Calorimetry

Kilocalorie per Hour Square Meter (kcal/(h·m²))

1.163 W/m².

Origin: European thermal engineering.

Current use: Building physics, Solar thermal

Erg per Second Square Centimeter (erg/(s·cm²))

1 erg/(s·cm²) = 0.001 W/m².

Origin: CGS system.

Current use: Astrophysics, Microscale heat transfer

Horsepower per Square Foot (hp/ft²)

1 hp/ft² = 8026.94 W/m².

Origin: Mechanical engineering.

Current use: Engine cooling, Industrial systems

Common uses for heat flux density conversions

Used for solar irradiance, thermal insulation, electronics cooling, and climate research.

Frequently asked questions about heat flux density

How many BTU/(h·in²) is 1 W/m²?+

1 W/m² equals approximately 0.00012237 BTU/(h·in²).

What is heat flux density?+

Heat flux density is heat transfer rate per unit area, typically measured in W/m².

Which units are supported?+

Watts per square meter and BTU per hour-square inch.