Free
Point-by-point
Live 3D preview
Lighting calculator
Quick illuminance estimate for a rectangular room: set a target in lux or a number of luminaires and see the layout, the lux map and the room in 3D.
Free, ready-to-embed lighting calculator — pick a style and your brand color, copy the snippet, done. It loads in an iframe, so it never clashes with your page styles.
Style and color apply to the tool right below — what you see is what the embedded widget looks like.
Top view · work plane
3D view
Drag to rotate
Average
—lx
Minimum
—lx
Maximum
—lx
Uniformity U₀
—
Luminaires
—
Layout
—
Total flux
—lm
Spacing
—m
How it is calculated
Real light curve
Each luminaire uses the same luminous intensity curve as our IES generator, not just a beam angle.
Point by point
Illuminance is summed from every luminaire at a grid of points on the work plane: inverse square law and cosine of incidence.
One reflection
Light reflected once from walls and floor is added using the reflectances above. Further reflections are ignored, so real rooms are slightly brighter.
Maintained values
All numbers are multiplied by the maintenance factor — what the room gives after lamps age and get dirty, as standards require.
Estimate, not a lighting design
Empty rectangular room, ceiling-mounted luminaires, regular grid. For furniture, windows, emergency or road lighting use a full calculation in DIALux, Relux or our workspace.