Beam Angle [Online Calculators] – The Best Way To Select The Light

We all require proper lighting in our homes and workplaces. However, selecting the right type of lighting entails more than just considering the brightness, functionality, and efficiency of the light. Another aspect of selecting the right lighting that we should consider if we want to maximize lighting in our homes and offices is the beam angle.

So, what exactly is the beam angle, and what role and importance do it play in selecting the best lighting for your needs? Here’s everything you need to know about beam angles and how they affect your lighting requirements.

The explanation of the beam angle

The explanation of the beam angle

The truth is that every light source, from the most basic candle to an LED light, has a beam angle. The beam angle is essentially a measurement of the distribution of light.

This is the angle formed by opposing points on the beam axis at which the intensity drops to 50% of its maximum. A spotlight has a narrow beam angle and a smaller illumination circle. A floodlight has a large circle of illumination and a wide beam angle.

The beam angle and the distance between the bulb and the illuminated surface determine the illuminated area. A larger illuminated circle will result from increasing the distance between the bulb and the surface.

A narrower beam angle will usually result in more brightness or more lumens for the same wattage because the light is concentrated on a smaller area. This is typically accomplished through the use of optics, such as reflectors or lenses.

To give you a better idea, a standard light bulb has a 360-degree beam, which means the light shining from it will surround the area but will not be very intense. Some types of lighting have narrower beam angles than others, resulting in more intense lighting; this includes downlights, particularly GU10 LED downlights.

The beam angle of such lights is frequently around 40 degrees or so, with the beam angle being no more than 5 degrees greater than the industry standard.

Read more: Recessed Lighting Calculator How much light is sufficient?

The truth about choosing lights with wider beam angles

When you choose a light with a wider or broader beam angle, you don’t necessarily get a brighter light; instead, you get light that is more evenly distributed. The brightness remains constant, but the intensity of the beam increases.

The brightness is expressed in lumens, whereas the intensity is expressed in candelas. One thing to keep in mind is that if you choose a wider beam angle, the light will be less intense, and the center of the light beam will not reach as far. Lighting can have a greater impact in a room if the beam angle is chosen correctly.

Another thing to keep in mind is that it’s not just about wider or narrower beams; the distance between lights will also have an effect. If you place four lights with 40-degree beams two meters apart in a room, you may end up with a dark, dim area in the middle.

“OK, I’ll install lights with wider beams,” you may think. This, however, is not a guaranteed solution. Even if you install four lights with 60-degree beams in the room, there may still be that dark, unlit area in the center.

So, what is the solution? It’s simple: instead of just using four downlights, increase the number to nine to improve light uniformity.

Where should lights with wider beam angles be used?

A light with a narrow beam angle – as little as 25 degrees, for example – is known as a spot. Flood lighting is used when you choose lights with wider beam angles of about 60 degrees. Hence, the big question is: where are the best places to use lights with varying beam angles?

Lounging areas are ideal for wider beam angles
Lounging areas are ideal for wider beam angles

Consider a lounging area, for example. Lounging areas are ideal for wider beam angles because the area does not need to be overly bright – typical tasks performed in a lounge area include watching television, relaxing, or reading, so lighting that is too focused or intense is not required.

Narrower beams (around 25 degrees) on the other hand, are often better suited to rooms with higher ceilings, such as a library or a study room.

Lights with beam angles ranging from 35 degrees to 45 degrees are typically appropriate for all other rooms in your home or office, but this will also depend on the spacing of the lights and their application.

Which lights should I use?

Actually, the best types of lights to choose for proper beam angles are LED downlights and GU10 LED lights. These lights are no longer limited to the standard 40-degree beam angle; they are now available in a wider range of beam angles, including 60 degrees.

More information on 60-degree beams

Choose a light with a beam angle of 60 degrees if you have a large room that you want to properly illuminate with the right beam angle. Even though the wider angle does not provide as much intense light, it is more evenly distributed throughout the room.

Furthermore, if you choose downlights with 60-degree beams and higher lumens, you won’t need to install as many downlights in that room. The room will already appear more uniform.

However, keep in mind that some rooms may not work well with lights with 60-degree beam angles, while others may work well with lights with 40-degree beam angles.

The goal is to ensure that the lighting in the room is uniform and symmetrical. There should be no dark spots in the room, as well as no excessively hot spots.

Read more: Illuminance Calculator: All-to-know about Calculating Illuminance

Other critical factors to consider

There are additional considerations to be made. The average lux (also known as brightness), the working plane, the reflectance, and, of course, the proper downlight are all examples of these.

Other critical factors to consider
Other critical factors to consider

When it comes to lux levels, the lighting industry has some standard lux levels for various rooms in the home, such as the kitchen (300 lux), bathroom (150 lux), bedroom (150 lux), and dining room (100 to 200 lux). Determine the functionality of a room before determining the best lux level for it.

What tasks are carried out in that room? This will assist you in determining the best lux levels for the various rooms in your home.

Meanwhile, the working plane is the height from which you will compute your standard lux levels in a room. In hallways, for example, the working plane is the floor, whereas in kitchens, the working plane is the worktops.

The reflectance of a room refers to how light reflects in that space. For example, if you have white or glossy walls and use wide beams, the light will not be lost in the walls and will instead reflect back.

However, if you use wide beams in a room with dark walls, the light will not reflect back but will be absorbed. You should also consider the appropriate downlights.

The highest lumen ratings, as well as the lowest watts, are ideal for downlights. This is measured in lumens per watt. You should go with a minimum of 5W, which equates to 50 lumens/watt. Downlights with 800 lumens and beam angles of 60 degrees are ideal for large rooms.

Last but not least, it is preferable to have bright downlights with wider beams in large rooms, and dimmer downlights with 40-degree beams in smaller areas or rooms, as long as they are close together.

Determine the beam angle

The beam angle value appears to be a little non-descriptive at times. Estimation is frequently difficult due to the influence of the distance between the lamp and the floor or wall. The formula and calculator below will assist you in determining the best fitting beam angle.

The formula for beam angle

The formula for beam angle

You can calculate the beam angle with all parameters using the trigonometric function (angle function) below.

α= 2 * (arctan (Ø2*d))


  • α: Beam angle
  • Ø: Diameter of the surface or object to be illuminated
  • d: Distance between lamp and surface or object
  • arctan: Inverse function of the tangent for angle calculation

Read more: Power Consumption Calculator Of Any Electrical Equipment

Online beam angle calculator

The calculator assists you in determining the precise beam angle. The direct relationship between the beam angle, the diameter of the light circle, and the distance to the illuminated object can be calculated here (table, wall, work surface, floor, picture). This allows you to calculate the best beam angle for your application and use it to make a purchasing decision.

Online beam angle calculator ở đây


#1. What exactly is the LED beam angle?

When no optical material is used, LEDs typically emit light at a 120-degree angle. However, for some LEDs, such as TH LEDs and Power LEDs, an optical material known as primary optical can be placed on the LED package. As a result, the LED package can have a light angle of 30, 60, or 90 degrees by default.

#2. What is a beam angle of 60 degrees?

Wider beam angles of 60 degrees are referred to as flood beams, and even wider beams are referred to as wide flood beams. In a lounge area, one of the best examples of using a wider beam, such as 60 degrees, would be.

#3. What is a flood light’s beam angle?

Flood light’s beam angle
Flood light’s beam angle

Floodlights typically have a beam spread of more than 45 degrees and up to about 120 degrees; however, some flood lights may have a beam as narrow as 25 degrees. If you’re looking for a light with such a narrow beam angle, you might be better off looking at spotlights.

#4. What is a beam angle of 36 degrees?

Downlights with a beam angle of 36 degrees are ideal for use in offices and homes. It is, however, dependent on its application and light spacing. It is ideal for use in domestic household ceiling-mounted appliances because it provides a softer, more general light.

#5. What is a beam angle of 40 degrees?

The standard beam angle (if such a thing exists) is 40 degrees. This is a medium spread beam with a good mix of intensity and coverage. You didn’t have much of a choice when it came to GU10 halogens, and if you still have any in your home, chances are they’re 40 degrees.

#6. What exactly is a 360-degree beam angle?

The maximum beam angle that can be used is 360 degrees. This type of light illuminates the entire circumference of the bulb. Tube lights for signs are a popular 360-degree product that we carry.


I hope you found this article useful in broadening your understanding of beam angle. As a result, you will have a positive lighting installation experience. If it was helpful to you, please share it so that others can benefit as well.

Thank you for your time! 

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