FastCalc powered by DIALux, fast calculation tool for simple light calculations

The web-based fast calculation tool FastCalc powered by DIALux is the modern replacement for outdated fast calculation tables, and therefore a tool that will help SLV customers such as yourself to sell your products. The tool takes important parameters such as room size, room use, room characteristics and degree of reflection into consideration, visualises just-in-time reliable light calculations and is completely free of charge to you - available for downlights & pendants with integrated LED.


  • Use the tool to help you to make sales on site at your customer's
  • No knowledge of standards or research required
  • Number of mistakes is reduced due to predefined selection options
  • The tool can be used free of charge


No special software knowledge is required to carry out light calculations for rooms with the FastCalc Tool powered by DIALux. The tool is intuitive, therefore ensuring that it is easy to use.
Light planning can be used intuitively with the free online Tool FastCalc. You can enter the data that the tool requires for the calculation step by step. The requirements the standards make of the lighting are behind the input fields, and take room use and the visual task into consideration. These are displayed in the relevant fields automatically after selecting the application area, and are taken into consideration in the light calculation. These cannot be edited, therefore ruling out refraction errors.
We would be pleased to help you with defining the degree of reflection. You can use the colour ring to determine a colour or grey scale value of the wall, ceiling and floor by means of a mouse click or by entering the exact colour code (RAL). The degree of reflection of the selected colour is determined automatically and also taken into consideration in the calculation.

Light planning based on the degree of efficiency procedure

Our SLV fast calculation tool uses the degree of efficiency procedure, and calculates the number of luminaires which are required to achieve the required light intensity in the room.


A user-defined entry is also available for individual calculation results. These are in the drop-down menu, so that you, as someone who is familiar with the standards, remain flexible when the calculation takes place.

Specific rough calculation for initial quantity estimate
Keep the results of your rough calculation in a 2D visualisation as a PDF. Use FastCalc as sales support when advising your customer about light, and then conveniently send it by e-mail as an aide-memoire, including the quote.

As well as the number of luminaires that is required, you are also provided with a suggestion for the best possible arrangement of the luminaires.

FastCalc is available for downlights and pendants with fixed LEDs

1. Select product

2. Start tool

3. Enter parameters

4. Calculate & done

Your advantages at a glance

  • Quick and reliable results
  • Quick, intuitive operation
  • No knowledge of standards or special software knowledge required
  • Optimised for tablet and Smartphone
  • Sales support by means of competent and quick advice
  • Used directly on site at your customer’s

Light calculation for rooms

Once you have found a luminaire that appears to be suitable for your project, you need to know how many of these luminaires are required to achieve a certain light intensity.

Carry out your light planning and light calculation online. The SLV FastCalc Tool shows you how many luminaires will produce the required light intensity (Lux). Define the number of luminaires that is required for a room quickly and easily.

We will provide you with all of the necessary light planning for our luminaires free of charge. FastCalc is available for SLV downlights and SLV pendants with integrated LED.