Photometry Tools

Lumens to Candela Calculator

Convert total overall light flux output in lumens (lm) to directional intensity in candelas (cd).

Calculation Input

Luminous Intensity

0.00 cd

Solid Angle Coverage 0.00 sr

Solid Angle Beam Category Flood / Spot

How Candelas are Calculated from Lumens

Directional light source intensity in candelas ($cd$) is calculated by dividing the total overall luminous flux in lumens ($lm$) by the solid angle ($\Omega$) representing the emission cone size:

$$cd = \frac{lm}{2\pi \left(1 - \cos\left(\frac{\theta}{2}\right)\right)}$$

Where $\theta$ is the apex beam angle in degrees. The denominator represents the solid angle $\Omega$ in steradians.