Converting from Lumen per Square Foot (lm/ft²) to Phot (ph) | Illuminance

What is Lumen per Square Foot (lm/ft²)

Lumen per square foot (lm/ft²) is a unit of measurement used to quantify the illuminance of light falling on a surface. It measures the amount of visible light that illuminates a one square foot area.

What is Phot (ph)

Phot (ph) is another unit for measuring illuminance, representing the amount of illuminance that one lumen of light generates uniformly over a square meter.

Conversion Formulas

To convert from Lumen per Square Foot (lm/ft²) to Phot (ph), you can use the following formula:

1(lm/ft²)=0.001076391(ph)

And to convert from Phot (ph) to Lumen per Square Foot (lm/ft²), you can use:

1(ph)=929.0304(lm/ft²)

Examples

• 9 (lm/ft²) = 0.009687519 (ph)
• 9 (ph) = 8361.274 (lm/ft²)
• 11 (lm/ft²) = 0.0118403 (ph)
• 11 (ph) = 10219.33 (lm/ft²)
• 14 (lm/ft²) = 0.01506947 (ph)
• 14 (ph) = 13006.43 (lm/ft²)

Use this page to perform conversions between Lumen per Square Foot (lm/ft²) and Phot (ph) for your illuminance calculations.