This calculator is useful for calculating the luminous flux for LEDS where the angle is known.

1 candela of luminous intensity equals 1 lumen of luminous flux per steradian of solid angle, where a steradian respresents a cone whose surface area at the end equals the length of the cone squared.

where:

- Φ
_{v}is the luminous flux, in measured in Lumens (lm), - I
_{v}is the luminous intensity, measured in Candela (cd), and - Ω is the solid angle of the beam is measured in Steradian (sr).

Conversion from beam angle to solid angle (sterians) is done with this formula:

where:

- θ is the the beam angle measured in degrees.

Enter any two known values and press "Calculate" to solve for the other.