Photometry · Beam
Enter a beam angle and throw distance to see how wide the beam lands — its diameter and lit area. Drag the sliders and watch the cone update.
D = 2 × d × tan(θ / 2) · Area = π (D / 2)²
Presets:
| Angle | Typical use |
|---|---|
| 8–15° | Accent & artwork, narrow spot |
| 20–25° | Spot lighting, retail display |
| 36–40° | General accent, kitchen island |
| 55–60° | Flood, ambient fill, wall washing |
| 90°+ | Wide flood, low ceilings |
Working backwards instead? If you know the pool size you want and need to pick an optic, use the Beam Angle Calculator.
Worked example: a 24° beam thrown 3 m lands a pool 2 × 3 × tan(12°) = 1.28 m wide, covering about 1.3 m².