The formula to calculate Candela (\(cd\)) from Lumens (\(lm\)) is:

\[ cd = \frac{lm}{2 \pi (1 - \cos(\theta / 2))} \]

Where:

• \(cd\) is the luminous intensity in candela.
• \(lm\) is the luminous flux in lumens.
• \(\theta\) is the apex angle in degrees.