Calculadora de Iluminação
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
lumens = área × lux; lâmpadas = ceil(lumens / lm_lamp)
About this calculator
The Lighting Calculator helps determine the amount of light needed for a room, calculating total lumens, wattage, and number of fixtures. It uses the formula: required lumens = area (m²) multiplied by desired illuminance (lux), which varies by room use. Then, total lumens are divided by the lumens per lamp to get the number of lamps, rounding up.
This tool is useful for residential projects such as living rooms, kitchens, bedrooms, and home offices, where proper lighting impacts comfort and functionality. For example, a living room may need 150 lux, while a kitchen requires 300 lux. Simply enter room dimensions and activity type to get accurate recommendations.
When using the calculator, consider that lamp efficiency (lm/W) and ceiling height can affect results. Rooms with dark walls or high ceilings may require more lumens. The calculator provides an initial estimate; fine-tuning can be done based on furniture layout and surface colors.
Common pitfalls include confusing lux with lumen: lux measures illuminance on a surface, while lumen is the total light emitted. Also, light distribution and fixture type affect perception, so consulting a professional is recommended for complex projects.
Frequently asked questions
What is the difference between lumen and lux?
Lumen is the total amount of light emitted by a source, while lux is the amount of light hitting a surface per square meter. One lux equals one lumen per square meter.
How many lux are recommended for a bedroom?
For bedrooms, 100 to 150 lux is recommended for general lighting. For reading in bed, use a localized lamp with 300 to 500 lux.
Can I use the calculator for commercial spaces?
Yes, but recommended lux levels for offices, stores, and other commercial spaces differ. The calculator allows manual lux input, adapting to any environment.
Does ceiling height affect the calculation?
Yes, higher ceilings require lamps with higher luminous flux or more fixtures to maintain illuminance at the work plane. The calculator considers area but not height; adjust lux manually if needed.
How to choose the right lamp after calculation?
With the number of lamps and total lumens, choose LED lamps with suitable color temperature (2700K-3000K for cozy spaces, 4000K-5000K for work areas) and a color rendering index (CRI) above 80.