Lumen per Square Foot to Phot Conversion

Convert between Lumen per Square Foot and Phot quickly and accurately.

lm/ft²
ph

How to Convert Lumen per Square Foot to Phot

Conversion Formula

1 lm/ft² = 0.001 ph
1 ph = 929.03 lm/ft²

Example

Convert 15 lm/ft² to ph:

15 lm/ft² = 15 × 0.001 ph = 0.016 ph

Unit Information

Learn about the illumination units you're converting between

Lumen per Square Foot

lm/ft²

Definition

The Lumen per Square Foot is an imperial unit of illuminance equal to approximately 10.76 lux, representing the luminous flux per square foot. It is commonly used in countries employing the imperial system for lighting design and illuminance measurements.

History/Origin

Developed in countries using imperial units as a practical measure of illuminance. It provides a familiar reference for lighting professionals working with imperial measurements and is commonly used in architectural lighting and building design.

Current Use

Widely used in the United States and other imperial-system countries for lighting design, architectural applications, and general illuminance measurements. It provides a practical unit for lighting professionals and is commonly referenced in building codes and lighting standards.

Multiplier

10.764

Offset

0

Phot

ph

Definition

The Phot is a CGS unit of illuminance equal to 10,000 lux, representing one lumen per square centimeter. It is a larger unit used for measuring very high levels of illumination, particularly in scientific and technical applications where high light intensities are common.

History/Origin

Developed as part of the CGS system of units, where the phot provided a convenient way to express high illumination values. It was widely used in scientific literature and technical applications before the adoption of SI units became standard practice.

Current Use

Primarily found in older scientific literature and specialized technical applications. It provides a practical scale for measuring very bright light sources and is still occasionally referenced in photometric research and historical technical documents.

Multiplier

10000

Offset

0

Lumen per Square Foot to Phot Conversion Table

Lumen per Square Foot [lm/ft²] Phot [ph]
1 lm/ft² 0.001076 ph
10 lm/ft² 0.010764 ph
25 lm/ft² 0.02691 ph
50 lm/ft² 0.05382 ph
100 lm/ft² 0.107639 ph
0 lm/ft² 0E+0 ph
-10 lm/ft² -0.010764 ph
-40 lm/ft² -0.043056 ph