Convert Lumen per Square Foot to Lumen per Square Inch
Type the number of lumens per square foot that you wish to convert to lumens per square inch.
How to Convert Lumens per Square Foot to Lumens per Square Inch
The lumen per square foot and lumen per square inch are both units of illuminance. 1 lumen per square inch equals 144 lumens per square foot. This means to convert lumens per square foot to lumens per square inch, you divide by 144.
Formula
Step-by-Step Example
Convert 5 lm/ft² to lumens per square inch:
We need to convert lumens per square foot to lumens per square inch
Since 1 lm/in² = 144 lm/ft², divide by 144
5 ÷ 144 = 0.0347222222
5 lm/ft² = 0.0347222222 lm/in²
Lumen per Square Foot to Lumen per Square Inch Conversion Table
Quick reference table for common lumen per square foot to lumen per square inch conversions. Click any value for detailed calculation.
| Lumens per Square Foot (lm/ft²) | Lumens per Square Inch (lm/in²) |
|---|---|
| 0.1 lm/ft² | 0.0006944444 lm/in² |
| 0.5 lm/ft² | 0.0034722222 lm/in² |
| 1 lm/ft² | 0.0069444444 lm/in² |
| 2 lm/ft² | 0.0138888889 lm/in² |
| 5 lm/ft² | 0.0347222222 lm/in² |
| 10 lm/ft² | 0.0694444444 lm/in² |
| 25 lm/ft² | 0.1736111111 lm/in² |
| 50 lm/ft² | 0.3472222222 lm/in² |
| 100 lm/ft² | 0.6944444445 lm/in² |
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.
Lumen per Square Inch (lm/in²)
Lumens per square inch (lm/in²) equals 1,550 lux or 144 foot-candles. Used for high-intensity illumination of small areas: display lighting, inspection systems, and microscopy. One lm/in² = 144 lm/ft². Rarely used; lux or foot-candles preferred.
Frequently Asked Questions
How do I convert lumens per square foot to lumens per square inch?
To convert lumens per square foot to lumens per square inch, divide the value by 144. For example, 10 lm/ft² = 0.0694444444 lm/in².
How many lumens per square inch are in 1 lumen per square foot?
1 lumen per square foot equals 0.0069444444 lumens per square inch.
What is the formula for lumens per square foot to lumens per square inch?
The formula is: lm/in² = lm/ft² ÷ 144.