Lumens necessários
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
This calculator helps determine the required lumens to light a space efficiently. Lumens measure total visible light emitted, while lux measures light intensity on a surface. The formula used is Lumens = Area (m²) × Target Lux. For example, a 10 m² room with 300 lux requires 3,000 lumens.
It's useful for residential or commercial projects, such as planning lighting for living rooms, offices, or kitchens. Lux levels vary by use: 100-200 lux for hallways, 300-500 for lounges, and up to 1,000 for specific work areas. This calculation guides the selection of appropriate bulbs or fixtures.
Caveats: the result is theoretical. Actual efficiency depends on factors like wall reflectivity, obstructions, and bulb type (LED, fluorescent, etc.). Always add 20% extra to account for light loss. Avoid overestimating, as excessive brightness can cause eye strain.
Frequently asked questions
What is lux and how to set the target level?
Lux measures light intensity per square meter. Typical values: living rooms (300-500 lux), study areas (500-750 lux), kitchens (300-500 lux). Adjust based on the room's primary use.
Should natural light be considered?
Yes. Subtract 30-50% from the calculation if the space has large windows or significant daylight.
How to use the result for LED bulbs?
Add all lumens needed and divide by the number of bulbs. Example: 3,000 lumens ÷ 3 bulbs = 1,000 lumens per bulb.
Is the calculation valid for all light types?
No. Traditional bulbs (incandescents) are less efficient than LEDs. Adjust the result based on your chosen technology.