Candela to Lux Calculator

What is Candela and Lux?

Candela (cd) is the SI base unit of luminous intensity, which measures the amount of light emitted by a source in a particular direction. Lux (lx) is the SI derived unit of illuminance, which measures the amount of light that falls on a surface area.

The Candela to Lux Formula

The formula for converting candela to lux is:

\[E = \frac{I}{d^2}\]

Where:

• \(E\) = Illuminance (lux)
• \(I\) = Luminous intensity (candela)
• \(d\) = Distance from the light source (meters)

Step-by-Step Candela to Lux Calculation

1. Identify the luminous intensity in candela (I) and the distance from the light source (d).
2. Ensure the distance is in meters. If it's in feet, multiply by 0.3048 to convert to meters.
3. Square the distance (d²).
4. Divide the luminous intensity by the squared distance (I / d²).
5. The result is the illuminance in lux (E).

Example Calculation

Let's calculate the illuminance for a light source with 1000 candela at a distance of 2 meters:

1. \(I = 1000 \text{ cd}\), \(d = 2 \text{ m}\)
2. \(d^2 = 2^2 = 4 \text{ m}^2\)
3. \(E = \frac{1000}{4} = 250 \text{ lux}\)

Visual Representation

This diagram illustrates how a 1000 candela light source creates an illuminance of 250 lux at a distance of 2 meters. The yellow point represents the light source, and the gradient shows how the light intensity decreases with distance.