Understanding the difference between lumens and candela is essential when evaluating light performance. Lumens measure the total amount of visible light, while candela measures the light’s intensity in a particular direction.
This chart provides quick reference conversions from lumens to candela based on different beam angles.
| Beam Angle (°) | Solid Angle (sr) | Candela (cd) = 100 lumens / sr |
|---|---|---|
| 10° | 0.024 | 4166.67 cd |
| 15° | 0.054 | 1851.85 cd |
| 20° | 0.095 | 1052.63 cd |
| 30° | 0.214 | 467.29 cd |
| 40° | 0.379 | 263.85 cd |
| 60° | 0.841 | 118.91 cd |
| 90° | 1.840 | 54.35 cd |
| 120° | 3.142 | 31.83 cd |
| 150° | 4.145 | 24.13 cd |
| 180° | 6.283 | 15.92 cd |
How This Works
The formula used to calculate candela is:
Candela = Lumens ÷ [2π × (1 – cos(θ ÷ 2))]
Where θ is the beam angle in degrees, and the result is based on the beam’s solid angle in steradians.