1. What is a Lumens per Square Foot Calculator?

Definition: This calculator determines the luminous flux per unit area by dividing total lumens by the area in square feet.

Purpose: It helps in lighting design to ensure adequate illumination levels for various spaces.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Lumens/sq ft — Illuminance (luminous flux per unit area)
• Total Lumens — Total light output (luminous flux)
• Area — Space area in square feet

Explanation: The total light output is divided by the area to determine how concentrated the light is in the space.

3. Importance of Lumens per Square Foot Calculation

Details: Proper lighting levels affect visibility, mood, and productivity. Different spaces require different illuminance levels.

4. Using the Calculator

Tips: Enter the total lumens of your light source(s) and the area of your space in square feet. Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a good lumens per square foot value?
A: Typical recommendations: 10-20 lm/ft² for ambient lighting, 30-50 lm/ft² for task lighting, 70+ lm/ft² for detailed work.

Q2: How do I find total lumens for multiple lights?
A: Sum the lumens of all light sources in the space (check product specifications).

Q3: Does this account for light loss factors?
A: No, consider multiplying the result by 1.25-1.5 to account for fixture efficiency and light loss over time.

Q4: How does this relate to foot-candles?
A: 1 foot-candle ≈ 1 lumen per square foot, but foot-candles measure light received while lumens measure light emitted.

Q5: What's the difference between lumens and watts?
A: Lumens measure light output, while watts measure energy consumption. LED lights produce more lumens per watt than incandescent.