watt per square meter to BTU per hour square foot converter

Convert watt per square meter to BTU per hour square foot in the Irradiance family. See a sample calculation, unit definitions, and the interactive converter.

Example conversion: 1 W-m2

0.3169983301 BTU per hour square foot

This example is calculated from the same unit registry used by the interactive converter.

Formula and unit definitions

Convert incident radiant power per unit area for optics and radiometry.

target value = source value × source factor ÷ target factor

Source unit: watt per square meter (W-m2), factor 1, offset 0.

Target unit: BTU per hour square foot (Btu-h-ft2), factor 3.15459075, offset 0.

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Important note

The calculation is performed locally from the listed unit definitions. Display results are rounded for readability; high-precision and regulated work should use the governing standard and appropriate significant figures.

For high-precision, regulated or safety-critical use, check the underlying standard and its required precision. Historical and approximate units are identified in their names or family descriptions.

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