Light spot and illuminance from one luminaire
Enter the distance to the surface, the beam angle and the luminous flux — we will work out the spot diameter and the illuminance inside it.
From the luminaire to the floor, table or wall
From the luminaire datasheet, e.g. 24°, 36°, 60°
Optional. If the fitting has a range, e.g. 36–60°, enter the upper value here.
Luminous flux of one luminaire
Light spot diameter
1.62 m
- Spot area
- 2.07 m²
- Illuminance at the centre
- 416 lx
- Average illuminance in the spot
- 386 lx
- Luminous intensity
- 2,601 cd
The calculation assumes all the flux sits inside the stated angle, which is how it is quoted for reflector luminaires. With a wide diffuser the real illuminance will be slightly lower.