Convert Lumen per Square Foot to Phot

Convert lumens per square foot to phots by entering a value below.

1 lm/ft² (lumens per square foot) = 0.001076391 ph (phots)

How to Convert Lumens per Square Foot to Phots

The lumen per square foot and phot are both units of illuminance. 1 phot equals 929.03039997 lumens per square foot. This means to convert lumens per square foot to phots, you divide by 929.03039997.

Formula

phots = lumens per square foot ÷ 929.03039997

Step-by-Step Example

Convert 5 lm/ft² to phots:

1
Convert 5 lm/ft² to phots

We need to convert lumens per square foot to phots

2
Apply the formula

Since 1 ph = 929.03039997 lm/ft², divide by 929.03039997

5 ÷ 929.03039997 = 0.0053819552

Answer

5 lm/ft² = 0.0053819552 ph

Lumen per Square Foot to Phot Conversion Table

Quick reference table for common lumen per square foot to phot conversions. Click any value for detailed calculation.

Lumens per Square Foot (lm/ft²) Phots (ph)
0.1 lm/ft² 0.0001076391 ph
0.5 lm/ft² 0.0005381955 ph
1 lm/ft² 0.001076391 ph
2 lm/ft² 0.0021527821 ph
5 lm/ft² 0.0053819552 ph
10 lm/ft² 0.0107639104 ph
25 lm/ft² 0.026909776 ph
50 lm/ft² 0.0538195521 ph
100 lm/ft² 0.1076391042 ph

About These Units

Lumen per Square Foot (lm/ft²)

Lumens per square foot (lm/ft²) is identical to foot-candles. The defining relationship: one foot-candle = one lumen per square foot. Used in US lighting calculations: lumens needed = foot-candles × square feet. Standard in American architectural lighting design.

Phot (ph)

The phot (ph) is the CGS unit of illuminance equal to 10,000 lux or 1 lumen per square centimeter. Very bright: full sunlight is about 10 phots. Found in older scientific literature. One phot = 929 foot-candles. Largely replaced by lux in modern usage.

Frequently Asked Questions

How do I convert lumens per square foot to phots?

To convert lumens per square foot to phots, divide the value by 929.03039997. For example, 10 lm/ft² = 0.0107639104 ph.

How many phots are in 1 lumen per square foot?

1 lumen per square foot equals 0.001076391 phots.

What is the formula for lumens per square foot to phots?

The formula is: ph = lm/ft² ÷ 929.03039997.