Lux to watts calculator
Lux to watts calculator
What Lux to watts calculator does
The Lux to watts calculator on RapidTables converts illuminance measured in lux to equivalent power output in watts. Users enter a light level value in lux, choose the light source or input luminous efficacy in lumens per watt, and specify surface area or spherical radius. The tool instantly returns the calculated power in watts, eliminating the need for manual physics equations. It supports multiple light source presets with typical efficacy values and accepts both metric and imperial area measurements, making it accessible for diverse professional and personal projects.
How to use the RapidTables Lux to watts calculator
- 1
Enter the illuminance value in lux (lx) in the designated field
- 2
Select a light source from the list or input the luminous efficacy in lumens per watt (lm/W)
- 3
Choose surface area in square feet/meters or enter spherical radius in feet/meters
- 4
Press the Calculate button to view the power result in watts (W)
Best for
Lighting designers, engineers, and anyone needing to convert between lux and watt units for specific applications, particularly those working with predefined light source types or mixed unit systems.
Limitations
- Predefined luminous efficacy values are typical averages, not exact for every bulb
- Requires knowledge of the light source's efficacy for accurate results
- Surface area or radius must be provided for calculation; cannot compute with lux alone
Lux to watts calculator FAQ
- Can I use this calculator if I don't know the luminous efficacy of my light source?
- Yes, the tool includes a dropdown menu with typical efficacy values for common light sources such as LED, fluorescent, and incandescent bulbs, so you can select the closest match without manual lookup.
- Does the calculator work with both metric and imperial units?
- The calculator supports both square meters and square feet for surface area, as well as meters and feet for spherical radius, allowing users to input measurements in their preferred unit system.
- How accurate is the power result given by the calculator?
- The results are based on standard luminous efficacy values typical for each light source type; actual power draw may vary depending on the specific bulb model and manufacturer specifications.
- Is there a way to convert from watts back to lux?
- RapidTables provides a separate 'Watts to lux calculator' on the same page for reverse conversion from power to illuminance, using the same efficacy and area parameters.