For some light bulbs and illuminants, there are both candela and lumen values indicated on the packaging. But what is the relationship between lumens and candela and how can these values be converted? Here you will find a handy lumen candela calculator for easy conversion.
Candela to Lumen Conversion
The luminous intensity of a light source is specified in candela. This is the luminous flux emitted in a specific direction in lumens. Especially for highly directional LED bulbs such as spots or LED recessed spotlights, the luminous intensity is sometimes indicated on the packaging or in the data sheet in addition to the luminous flux.
Candela Lumen Comparison
Both values are transmission units. But a comparison of these values seems to be difficult, because the luminous intensity additionally is direction-dependent. The luminous intensity results from the luminous flux related to the solid angle.
In case of two lamps with the same lumen value and different beam angles, the luminous flux is distributed over a different solid angle. So the lamp with the smaller beam angle has the higher candela value.
Lumen to Candela Converter
The calculator helps you to easily convert between candela and lumens as well as lumens and candela. First select your desired calculation type and then enter the lumen or candela value and the beam angle of your lamp. After calculation the result size will be displayed.
Candela Lumen Formula
The formula to convert between candela and lumen is:
Luminous intensity (candela) = Luminous flux (lumen) / Solid angle (steradian)
I = Φ : Ω
Important: The solid angle must not be mixed up with the beam angle. This would require a further conversion. The above online calculator performs this step automatically for you.
Both the lumen and candela values are used to describe the brightness of LED lamps. Due to the directionality of the luminous intensity, a direct comparison is not possible. But with the lumen candela calculator, you can easily convert both values to the other and compare them afterwards.