LIGHT PLUS UK · Photometric tools

Beam & Lux Calculator

Pick a LIGHT PLUS fitting, or set your own beam and output, then change the mounting height to see how much light reaches the floor or the desk, and how wide the pool of light is.

Light source

Measure the light on

Colour temperature

Changes the colour of the picture only — lux figures do not change with colour temperature. Not every fitting is built in all seven; the product page lists the ones you can order.

Lux across the floorMove over the graph to read a point

Directly below

lux at the centre

Average in beam

Beam diameter

Spill diameter

Before you download

Who shall we send it to?

So we can help with the project behind it. One time only — we will not ask again on this device.

Your work address, if you have one.

Are you

We use these details to answer your enquiry and nothing else. How we handle them.

What these figures are

Figures are for one fitting on its own, aimed square at the surface it lights, when new. They leave out light reflected from walls and ceiling and the extra light from neighbouring fittings, so a real room will usually be brighter than this. Plan a full scheme with a lighting design (DIALux or Relux) using our IES files.

Product figures come from LIGHT PLUS calculated photometric data, based on each product's stated output and beam. They are nominal values, not laboratory measurements.

How it is worked out

Lux at a point: E = I(γ) × cos³γ ÷ h², where I(γ) is the fitting's intensity at that angle and h is the height above the surface.

Beam diameter uses the 50% intensity angle, spill diameter uses the 10% angle. Average in beam is the light that actually lands inside the beam circle divided by its area.