1. What is the Foot Candles Formula?

The Foot Candles formula calculates illuminance by dividing the total luminous flux (in lumens) by the area (in square feet). It provides a measure of how much light is falling on a surface area.

2. How Does the Calculator Work?

The calculator uses the Foot Candles formula:

Where:

• \( FC \) — Foot Candles (illuminance)
• \( L \) — Lumens (luminous flux)
• \( A \) — Area in square feet

Explanation: The formula calculates the illuminance level by distributing the total light output (lumens) over the area being illuminated.

3. Importance of Foot Candles Calculation

Details: Foot candles measurement is crucial for lighting design, ensuring adequate illumination for various tasks and spaces while optimizing energy efficiency.

4. Using the Calculator

Tips: Enter total lumens and area in square feet. Both values must be positive numbers greater than zero for accurate calculation.

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 is falling on a surface.

Q2: What are typical foot candle requirements?
A: Requirements vary by application: general lighting (10-20 fc), reading (30-50 fc), detailed work (50-100 fc), surgery (1000+ fc).

Q3: How does this differ from lux?
A: Lux is the metric equivalent (lumens per square meter). 1 foot candle = 10.76 lux.

Q4: Why is this calculation important?
A: Proper lighting calculation ensures adequate illumination for tasks, reduces eye strain, and helps design energy-efficient lighting systems.

Q5: Can I use this for outdoor lighting?
A: Yes, the same formula applies, though outdoor lighting typically requires lower foot candle levels than indoor task lighting.