Convert Lumen per Square Foot to Phot
Convert lumens per square foot to phots by entering a value below.
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
Step-by-Step Example
Convert 5 lm/ft² to phots:
We need to convert lumens per square foot to phots
Since 1 ph = 929.03039997 lm/ft², divide by 929.03039997
5 ÷ 929.03039997 = 0.0053819552
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.