1. What is a Lumen to Candela Calculator?

Definition: This calculator converts luminous flux (lumens) to luminous intensity (candela) for a light source with a specific beam angle.

Purpose: It helps lighting designers and engineers understand the directional intensity of light sources.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( cd \) — Luminous intensity (candela)
• \( Lumens \) — Total luminous flux
• \( \theta \) — Beam angle (degrees)
• \( \pi \) — Pi constant (~3.14159)

Explanation: The formula accounts for how the light is distributed within the specified beam angle.

3. Importance of Lumen to Candela Conversion

Details: Candela measures directional intensity, which is crucial for applications like spotlights, flashlights, and directional lighting where beam angle matters.

4. Using the Calculator

Tips: Enter the total luminous flux in lumens and the beam angle in degrees (default 30°). Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between lumens and candela?
A: Lumens measure total light output, while candela measures light intensity in a specific direction.

Q2: Why does beam angle affect candela?
A: A narrower beam concentrates the same lumens into a smaller area, resulting in higher intensity (candela).

Q3: What's a typical beam angle for calculations?
A: Common angles are 15° (spot), 30° (narrow flood), and 60° (wide flood), but this varies by application.

Q4: How does this relate to lux?
A: Lux measures illuminance (lumens/m²) at a surface, which depends on both candela and distance from the source.

Q5: Can I use this for LED lights?
A: Yes, this calculation works for any light source where you know the total lumens and beam angle.