1. What is a Lumens to Foot Candles Calculator?

Definition: This calculator converts luminous flux (lumens) to illuminance (foot-candles) based on the area being illuminated.

Purpose: It helps lighting designers, architects, and engineers determine the appropriate lighting levels for various spaces.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( FC \) — Illuminance in foot-candles (fc)
• \( Lumens \) — Total luminous flux (lm)
• \( Area \) — Surface area in square feet (ft²)

Explanation: Foot-candles measure how much light is actually reaching a surface area (illuminance), while lumens measure the total light output (luminous flux).

3. Importance of Foot Candle Calculation

Details: Proper illuminance calculations ensure adequate lighting for tasks, safety, and comfort while optimizing energy efficiency.

4. Using the Calculator

Tips: Enter the total lumens of your light source and the area to be illuminated in square feet. Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a foot-candle?
A: A foot-candle is a unit of illuminance equal to one lumen per square foot. It measures how much light reaches a surface.

Q2: How many foot-candles are recommended for different spaces?
A: Offices typically need 30-50 fc, classrooms 30-75 fc, warehouses 10-30 fc, and detailed work areas may need 100+ fc.

Q3: What's the difference between lumens and foot-candles?
A: Lumens measure total light output (like a water hose's flow), while foot-candles measure light reaching a surface (like water hitting a specific area).

Q4: How do I find the lumens of a light fixture?
A: Check the product specifications - most LED bulbs list lumens on the packaging (e.g., 800 lumens = 60W incandescent equivalent).

Q5: Does this account for light loss factors?
A: No, this is a basic calculation. For professional designs, consider adding 20-30% more lumens to account for fixture efficiency, dirt accumulation, and other factors.