Watts and Lumen: How to Choose Best LED or Bulbs

Watts and lumens are two pieces of information present in lamps incandescent, fluorescent and LED. Watt is related to lamp consumption, while lumens is related to ambient lighting capacity. Learn how to choose the best one.

Watts and Lumen: How to Choose LED or Bulbs

What is watts

Watt (W) is the unit of measurement of the power of an electronic equipment. This value is obtained by multiplying the voltage (measured in volts) by the current (measured in amps).

Power is related to the electrical consumption of a device and not to the lighting capacity of a lamp, for example.

What is lumens

Lumens (Lm) is the unit of measure for the luminous flux that a lamp emits. This defines the illumination capacity of a lamp in the room, ie the greater the amount of lumens, the more light there will be in the room.

How to calculate and choose the ideal lamp

It is not enough just to choose a lamp for the greater number of lumens it has, since the higher the number, the more light the equipment emits.


Luminance (represented by lux ) is the ratio of luminous flux (lumens) to the area of ​​the environment. This measurement is calculated by dividing the lumen amount of a lamp by the ambient area (in square meters).

Following the standards determination, the minimum lux value for each environment is:

Living room (general light) 50 to 100
Living room (quick tasks) 150
Living room (read, study) 300
Dining room 50 to 200
Bedrooms (general light) 50
Bedrooms (Headboard) 150
Kitchen 300 to 500
Bathroom (general light) 100
Bathroom (mirror) 200
Hall 150
Staircase 100
Office 300 to 500
Garage 50

For example, considering a kitchen of 5 square meters and the minimum recommended quantity is 300 lux, this means that you need to find a lamp with at least 1,500 lumens or distribute two 750-lumen lamps.

Which lamp consumes less energy?

Then comes the wattage, the wattage indicated in the specifications of each lamp. To know which lamp consumes less, the amount of lumens is divided by its wattage.

From this it is known how much lumen a lamp emits for each watt consumed.

We have the notion that incandescent bulbs consume more than fluorescent bulbs and LED bulbs are more economical than fluorescent bulbs. However, the more energy efficient, the more expensive the product.


  • Incandescent lights produce 14 lumens for each watt consumed;
  • Fluorescent produces 50 for each watt consumed;
  • LEDs produce 85 for each watt consumed.

So, did it help clarify the doubt by buying a new light bulb?

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