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Candela to Lumen Calculator northerncult blog


Lighting is not just about brightness; it’s about understanding and harnessing the right amount of illumination for a given space or task. In the world of lighting engineering, two crucial measurements stand out: Candela and Lumen. While Candela measures the intensity of light emitted in a particular direction, Lumen quantifies the total amount of light emitted from a source in all directions.

Understanding the relationship between these two metrics is fundamental in designing effective lighting systems. Enter the Candela to Lumen Calculator with Apex Angle โ€“ a tool that bridges the gap between these measurements, offering invaluable insights for lighting professionals and enthusiasts alike.

Understanding Candela and Lumen Calculator

Before delving into the candela to lumen calculator, let’s grasp the essence of Candela and Lumen. Candela (cd) is a unit of luminous intensity, measuring the amount of light emitted by a source in a particular direction. It’s crucial in applications where light directionality matters, such as headlights or spotlights. Lumen (lm), on the other hand, quantifies the total amount of visible light emitted by a source, regardless of direction. This is especially useful when assessing the overall brightness of a light source, like in ambient lighting scenarios.


Why Calculate? The Importance of Candela to Lumen Calculator

The need to convert between Candela and Lumen arises from the diverse requirements of lighting design. Consider a scenario where you’re designing the lighting layout for a museum exhibit. Here, you need to ensure that each artifact is adequately illuminated without causing glare or overshadowing neighboring displays. By converting Candela to Lumen and vice versa, you can precisely tailor the lighting to meet these specific needs, achieving both functionality and aesthetics.

The Role of Apex Angle: Adding Precision to Measurements

In many lighting applications, the directionality of light emission is not uniform. This is where the concept of the apex angle comes into play. The apex angle represents the angular spread of light emitted by a source. For instance, a narrow apex angle indicates a more focused beam, while a wider angle signifies broader coverage. Incorporating the apex angle in Candela to Lumen calculations allows for even greater precision in lighting design, enabling engineers to fine-tune the distribution of light according to the requirements of the space.

Candela to Lumen Conversion Formula

The conversion from Candela to Lumen is a fundamental process that ensures precise illumination in various applications. Candela (cd) measures the intensity of light emitted in a specific direction, while Lumen (lm) quantifies the total amount of light emitted from a source. Converting between these units requires more than a simple numerical conversion; it necessitates consideration of the angular spread of light emission, known as the apex angle.

The conversion formula integrates this crucial factor, offering a comprehensive approach to translating luminous intensity into total luminous flux. It can be expressed as:


  • is the total luminous flux emitted by the source.
  • is the luminous intensity measured in Candela.
  • ๐œƒย is the apex angle of the light source in radians.

By incorporating the apex angle into the equation, the formula ensures accuracy in lighting design, enabling professionals to tailor their solutions to meet specific requirements with precision. From architectural lighting to automotive engineering and theatrical stage design, understanding and applying this conversion formula are essential for achieving optimal visibility, efficiency, and aesthetic appeal in illuminated spaces

Uses of Candela to Lumen Calculator with Apex Angle
  1. Architectural Lighting Design: Architects and lighting designers use the calculator to ensure optimal illumination of building facades, interiors, and landscapes. By factoring in the apex angle, they can achieve desired lighting effects while minimizing light spillage and energy wastage.

  2. Automotive Lighting: In automotive engineering, headlights and taillights must meet stringent safety and regulatory standards. The calculator helps automotive manufacturers determine the appropriate Candela and Lumen values for headlights based on factors such as beam pattern, apex angle, and road illumination requirements.

  3. Theatrical and Stage Lighting: Theater directors and stage designers rely on precise lighting control to create captivating performances. By converting Candela to Lumen with consideration for the apex angle, they can orchestrate lighting effects that enhance mood, highlight actors, and set the stage for immersive storytelling.

  4. Outdoor and Street Lighting: Municipalities and urban planners utilize the calculator to optimize street lighting efficiency and safety. By calculating Lumen output per Candela with respect to the apex angle, they can select lighting fixtures that maximize visibility while minimizing light pollution and energy consumption.

  5. Display and Exhibition Lighting: From trade show booths to museum exhibits, effective display lighting can significantly impact audience engagement. By converting Candela to Lumen and accounting for the apex angle, exhibitors can showcase products and artifacts with precision, drawing attention to key features and details.



Lumens in lighting

In lighting, the total quantity of light that a lighting device emits is measured in lumens. Lumens are represented as lm. An illumination device’s illumination area increases with its lumen value. The spread or divergence of the light that the gadget is emitting is not taken into account by the lumens unit.

Light Output = Lumens. Simply said, lumens, or lm, are a measurement of the total quantity of light from a lamp or other light source that is visible to the human eye.

Lighting Definition Candela Northerncult Blog Lighting Definition Candela Northerncult Blog

The term “candela” describes the amount of light that a lighting fixture emits in a specific direction. Candlepower is also known as candela. Candlepower measurements date back to a time when candles served as the main source of light. A candle of a given size emits roughly the same amount of light as one candela.


Although they each measure different properties of a lighting device, lumens and candela are both used in the measurement of lighting. Choosing lighting fixtures that are perfect for your workspace can be made easier if you understand the distinction between lumens and candelas.

When assessing the luminous efficacy of lighting fixtures in industrial environments, we employ both lumens and candelas. The relationship between candelas and lumens is generally represented by the following equation.

Understanding the distinction between candela and lumens will assist you in selecting the right lighting fixture for your building or area that needs to be lit. To light up an area, for example, you would need to install lights in an office building. For employees to walk around smoothly, corridors and storerooms must have the right amount of light.ย 

The device will emit light that is lighter and covers a broader area when its lumen value is higher. However, some staff members might use complex equipment, so they require overhead lighting that shines directly on the items they are handling. In these situations, you’ll need to purchase lighting fixtures after contrasting their candela ratings.

1 candela = 12.57 lumens



A foot-candle equals one lumen per square foot. This is a British measurement. Using the metric system, a lumen is measured by a square meter or a lux. Thus a foot candle is equivalent to approximately 10 lux or 10.57 lux.

1 foot-candle = 10.57 lux

Now that you know how to convert foot-candles to lumens (Lux) and Watts. it is easy to do the same for your own measurements. Simply substitute 50 for your own measurements.

  • To work out Lumens or Lux use the following Equation: Lumens = Foot-Candles x 10.76
  • To work out Watts use the following equations or lumens to watts: Watts = Lumens x 0.001496
  • You can also calculate the number of watts directly from the foot-candles by combining both equations and using the following: Watts = Foot Candles x 0.01609696 (This is because 10.76 x 0.001496 = 0.01609696)

Calculating and converting is very easy and shouldn’t take very long to do once you get used to it. As the number of lumens is just over 10 x foot candles.



In the transition to more sustainable lighting solutions, LED technology has emerged as a frontrunner, offering enhanced efficiency and longevity. One of the key metrics used to evaluate LED bulbs is their wattage equivalence to traditional incandescent bulbs. To match the brightness of a 60-watt incandescent bulb, an LED bulb typically requires significantly fewer watts.ย For An LED lightbulb, for instance, may generate the same amount of light as an incandescent bulb, which consumes 60 watts, but it needs a lot less energyโ€”8 to 12 watts.

In Conclusion: Enlightening Perspectives

The Candela to Lumen Calculator with Apex Angle serves as a beacon of precision in the realm of lighting design. By facilitating seamless conversion between luminous intensity and total luminous flux, this tool empowers lighting professionals to create environments that are both visually captivating and functionally efficient. As we continue to innovate in the field of lighting engineering, let us illuminate the world with knowledge, creativity, and purpose.