Lighting

Lumens Calculator

Convert room area and target lux directly into required light output.

Free interactive tool

Enter your details

lux
%
Method & guidance

How the Lumens Calculator works

Lumens equal square metres multiplied by lux, with a maintenance allowance for aging and dirt.

How to use this tool

  1. Collect accurate values for room area, target lux, maintenance allowance.
  2. Enter measurements in the displayed units and select the choices that match this project.
  3. Select Calculate / Generate, then compare the outputs with the stated Lumens Calculator method.
  4. Apply the result only after checking product specifications and real site conditions.

Example calculation or use case

For a worked Lumens Calculator example, use Room area = 20 m², Target lux = 200 lux, Maintenance allowance = 15 %. The tool then applies this method: Lumens equal square metres multiplied by lux, with a maintenance allowance for aging and dirt.

Frequently Asked Questions

What information does the Lumens Calculator use?

It uses the measurements and choices shown in the form. Lumens equal square metres multiplied by lux, with a maintenance allowance for aging and dirt.

How accurate is the Lumens Calculator result?

The calculation is mathematically consistent with the stated assumptions. Light-colored rooms reflect more useful light than dark, matte rooms. Real products, site conditions, and supplier specifications can still change the final decision.

Should I include an allowance?

Use the result as a planning baseline and keep a sensible reserve for site variation, delivery, or fitting.

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