Lumen to Candela Calculator
Convert lumens to candela with step-by-step calculations. Perfect for LED specifications, lighting design, and photometric calculations.
Luminous Flux to Luminous Intensity Converter
Common Lumen to Candela Conversions
Click on these links to see instant conversions with common values:
Understanding Lumen to Candela Conversion
Converting lumens to candela involves transforming total luminous flux to luminous intensity in a specific direction. This conversion is fundamental for understanding LED performance and lighting calculations.
Conversion Formula
Where:
• cd = candela (luminous intensity)
• lumens = luminous flux
• θ = beam angle in degrees
• π = 3.14159...
Key Concepts
- Lumens (lm): Total luminous flux - the total amount of visible light emitted by a source
- Candela (cd): Luminous intensity - the amount of light emitted in a particular direction
- Beam Angle: The cone angle where the luminous intensity is at least 50% of the maximum
- Solid Angle: The three-dimensional angle subtended by the light beam (measured in steradians)
Applications
| Light Source | Typical Lumens | Beam Angle | Approx. Candela |
|---|---|---|---|
| LED Spotlight | 1000 lm | 30° | 1432 cd |
| LED Floodlight | 2000 lm | 120° | 318 cd |
| LED Bulb | 800 lm | 270° | 64 cd |
| Car Headlight | 3000 lm | 20° | 8591 cd |
| Flashlight | 500 lm | 15° | 5729 cd |
Frequently Asked Questions
How do you convert lumens to candela?
Use the formula: cd = lumens ÷ (2π × (1 - cos(θ/2))), where θ is the beam angle. This converts total light output to directional light intensity.
What is the relationship between lumens and candela?
Lumens measure total light output (omnidirectional), while candela measures light intensity in a specific direction. The conversion depends on how the light is distributed (beam angle).
What is a candela in lighting?
A candela is the SI base unit of luminous intensity, measuring the amount of light emitted in a particular direction. It's approximately equal to the light emitted by one candle.