Lighting Design Tool
LED Beam Angle Calculator
Find the beam angle, beam spread or spot size for any LED track light or downlight. Enter two values below and get the third instantly.
Beam visualization
How to Use
Three Simple Steps
Measure twice, install once — the calculator does the math for you.
Measure the mounting distance
Measure from the fixture lens (light source) to the surface you want to illuminate. The bigger the distance, the larger the beam spread for the same beam angle.
Pick the beam angle
Choose your fixture's beam angle (e.g. 15° spot or 36° flood) or measure the beam diameter on the surface to find the angle you actually need.
Get the spot size instantly
The calculator shows the beam diameter at your mounting distance and a visual diagram of the cone. Fine-tune values until the spot covers your display or artwork.
Standard Beam Angles and Typical Uses
Most LED track lights and downlights are available in a few standard beam angles. Here is a quick guide:
| Beam angle | Category | Beam spread at 3 m (10 ft) | Best for |
|---|---|---|---|
| 10° | Ultra narrow spot | 0.5 m | Accents, logos, sculptures, long throws |
| 15° | Ultra narrow spot | 0.8 m | Highlighting small objects and artwork |
| 24° | Narrow spot | 1.3 m | Retail displays, wall washing, picture lights |
| 36° | Medium flood | 1.9 m | General accent and feature lighting |
| 60° | Wide flood | 3.5 m | General lighting, shelves, big displays |
| 90° | Extra wide flood | 6.0 m | Ambient light and short-throw coverage |
* Beam spread values are approximate (full beam angle, cone model). Actual distribution varies by reflector and lens optics.
FAQs
Beam Angle Questions, Answered
Common questions about LED beam angles, beam spread and spot size.
What is the beam angle of an LED light?
The beam angle (full angle) is the angle of the cone of light emitted by a fixture. It defines how tight or wide the light spreads: a 15° beam is a tight spot, a 60° beam is a wide flood.
How do you calculate beam angle?
Use the formula: beam angle = 2 × arctan(beam diameter ÷ (2 × mounting distance)). Enter your beam diameter and distance in the calculator above and it will do the math for you.
What is the difference between beam angle and field angle?
Beam angle is measured at 50% of maximum intensity (FWHM). Field angle is measured at 10% of maximum intensity and is wider. Most spec sheets list the beam angle at 50%.
Does beam angle change with distance?
No. The beam angle is fixed for a given fixture and optic. What changes with distance is the beam diameter (spot size) — the further the light, the wider the spot.
Which beam angle should I choose for retail display lighting?
For tight accents on products, use 10°–15°. For general display and shelving, 24°–36° works best. For wide shelving or wall washing, choose 60° or wider. Our team can also recommend optics for your project.
Not Sure Which Beam Angle You Need?
Tell us your application and mounting height — our engineers will recommend the right fixture and optics for free.