Candela to Lux Calculator

Enter Luminous Intensity (Candela): Enter Distance:

What is Candela?

The candela (cd) is a unit of luminous intensity in the SI system. It represents the brightness of some light in a given direction. For example, a candle gives out light at an intensity of almost one candela. It is a standard measurement for how bright or intense a light source appears, hence allowing for comparisons to be as consistent as possible across diverse lighting devices.

What is Lux?

Lux (lx) is the SI unit of illuminance. It is the measure of light per unit area. For example, one lux equals one lumen/square meter. Candela measures the intensity of light that is emitted. Lux, however, quantifies the intensity of light received at a certain location or area, and it takes into account how far away the point or area is from the emitting source of light.

You can also convert candela to lux by using the formula formula:

E_v(lx) = I_v(cd) / (d_(m))²

Candela to Lux Conversion

Formula: Candela to Lux with Distance in Meters

To calculate illuminance (Ev) in lux when luminous intensity (Iv) in candela and distance (d) in meters are known:

\[ E_v (\text{lux}) = \frac{I_v (\text{cd})}{(d (\text{m}))^2} \]

Where:

\(E_v\) = Illuminance in lux
\(I_v\) = Luminous intensity in candela
\(d\) = Distance from the source in meters

Formula: Candela to Lux with Distance in Feet

To calculate illuminance (Ev) in lux when luminous intensity (Iv) in candela and distance (d) in feet are known:

\[ E_v (\text{lux}) = 10.76391 \times \frac{I_v (\text{cd})}{(d (\text{ft}))^2} \]

Where:

\(E_v\) = Illuminance in lux
\(I_v\) = Luminous intensity in candela
\(d\) = Distance from the source in feet
\(10.76391\) = Conversion factor from square meters to square feet

Example Calculation (Meters)

If the luminous intensity is 50 candela and the distance is 2 meters:

\[ E_v = \frac{50}{2^2} = \frac{50}{4} = 12.5 \, \text{lux} \]

Example Calculation (Feet)

If the luminous intensity is 50 candela and the distance is 6 feet:

\[ E_v = 10.76391 \times \frac{50}{6^2} = 10.76391 \times \frac{50}{36} \approx 14.96 \, \text{lux} \]

How to use candela to lux conversion calculator?

Enter the luminous intensity (Iv): Input the light source’s luminous intensity in candela (cd).
Provide the distance (d): Enter the distance from the light source to the surface in meters or feet, depending on the calculator settings.
Select the unit of distance: Choose whether the distance is measured in meters or feet (if applicable).
Click “Calculate”: Press the calculate button to get the illuminance (Ev) in lux.
View the result: The calculator will display the calculated lux value, representing the illuminance at the given distance.