1. What is Lux (Illuminance)?

Lux (lx) is the SI unit of illuminance, measuring luminous flux per unit area. It indicates how much luminous flux is spread over a given surface area, representing the perceived intensity of light as seen by the human eye.

2. How Does the Calculator Work?

The calculator uses the illuminance formula:

Where:

• \( E_v \) — Illuminance in lux (lx)
• \( \Phi_v \) — Luminous flux in lumens (lm)
• \( A \) — Area in square meters (m²)

Explanation: The formula calculates how much light (in lumens) is distributed over a specific area to determine the illuminance level.

3. Importance of Lux Calculation

Details: Lux measurements are crucial in lighting design, photography, workplace safety standards, and architectural planning to ensure adequate illumination for various tasks and environments.

4. Using the Calculator

Tips: Enter the total luminous flux in lumens and the area in square meters. Both values must be positive numbers for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between lumens and lux?
A: Lumens measure total light output (luminous flux), while lux measures how much of that light falls on a surface (illuminance).

Q2: What are typical lux levels for different environments?
A: Moonlight is about 1 lx, office lighting 300-500 lx, direct sunlight can exceed 100,000 lx.

Q3: How does distance affect lux?
A: For a point source, illuminance follows the inverse-square law - doubling distance reduces illuminance to 1/4.

Q4: Can I use this for LED lighting calculations?
A: Yes, the formula works for all light sources as long as you know the total luminous flux in lumens.

Q5: How accurate is this calculation?
A: It provides theoretical illuminance assuming uniform light distribution. Real-world measurements may vary due to reflections, obstructions, and light source geometry.