Lux = lm/m²
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The Lux calculator from Lumen converts luminous flux into Lux, a measure of illuminance per square meter. It uses the formula: Lux = Lumen / m², dividing the light output by the area it covers. This tool is crucial for lighting design applications, such as architecture, photography, or electrical engineering, where precise light intensity calculations are required.
This conversion is practical for scenarios like determining lamp requirements for a room, adjusting studio lighting, or complying with safety standards. To use it correctly, input the total Lumen value and the area in square meters. Accuracy in input data is essential, as errors in area or light flow can lead to misleading results.
A common caution is to avoid confusing Lumen (light flux) with Lux (illuminance). Additionally, the calculator assumes uniform light distribution; in directional or non-uniform lighting cases, results may not match reality. Always verify the technical specifications of involved equipment.
Frequently asked questions
What is Lux?
Lux is a unit of illuminance, measuring the amount of light falling on a surface per square meter.
How does the Lux = Lumen/m² formula work?
The formula divides the total Lumen output by the area in square meters, representing how light intensity is spread across a space.
When should I use this calculator?
Use it in lighting projects to determine if a light source meets the requirements of a specific environment.
Do I need to convert units before using it?
Yes, ensure the area is in square meters and luminosity is in Lumens for accurate results.
What if the light isn't evenly distributed?
The calculator assumes uniform distribution. For directional light, consult a lighting specialist for manual adjustments.