How do you understand LEDs and watt equivalents?

27 février 2025

A truly complex topic, lighting is often seen as a matter for specialists. With this article, you’ll know all about LEDs and their watt equivalencies. The power of a light fixture will no longer be a mystery to you!

What are LED watts and LEDs?

The watt, symbolized as W, is the international unit of power or energy flow. One watt is equal to one joule per second.

This unit measures the electrical power produced by the light source, that is, its electrical consumption. With low-energy bulbs such as LEDs and compact fluorescent bulbs, this unit no longer indicates the lighting efficiency of a bulb but rather its energy consumption: the higher the wattage, the more electricity the bulb uses.

Until 2006, we chose the strength of our lighting by looking at the number of watts listed on a bulb. The more powerful the light, the more energy it consumed, and the higher its wattage.

Today, however, new types of bulbs can produce much more light while consuming significantly less energy:

They are called “compact fluorescents” because they produce light by exciting a fluorescent molecule.
Fluorescent light consumes much less energy than traditional incandescent lamps, which produce light by heating a metal filament.
Compact fluorescents also generate much less heat. However, we do not recommend compact fluorescent bulbs as they are difficult to recycle and highly polluting after use.
Energy consumption is therefore no longer a sufficient criterion for measuring a bulb’s strength.

The energy label, rated from A to G, defines the energy efficiency of a lamp. The closer to G, the more energy-consuming; the closer to A, the more efficient.

Equivalencies

Here is a chart showing the equivalences between incandescent, halogen, LED bulbs, and their respective power consumption.

For example, an LED bulb consumes 12 watts compared to 60 watts for an incandescent bulb with the same light output!

Decor tips on LED wattage

Each room in the house requires specific lighting. In a kitchen or bathroom, for example, the lighting needs are much greater than in a living room or bedroom, and each space has its own rules and requirements.

To light a part of your home effectively while creating a pleasant living space, it’s essential to learn a few lighting concepts. The lux is a unit of measurement for luminous flux and characterizes the amount of light received per unit of surface area.

Good lighting highlights areas you want to emphasize or bring attention to, such as living spaces where people gather and are naturally drawn to when entering a room: the dining room table, coffee table in the living room, couch, kitchen island, etc.

The choice of lighting depends on four criteria: the type of room to be lit, the desired ambiance, the appropriate color temperature of light, and the lighting distribution to make the most of each space.

Lighting strength adapts to activities and rooms:

Tasks like homework or meal prep require bright lighting, while activities like reading or watching TV call for softer, diffused lighting.

In an office, it’s essential to have strong lighting to avoid eye strain while working. Aim for at least 300 lux, or between 3,000 and 6,000 lumens, for sufficient comfort. A small desk lamp with a narrow beam angle can complement the general lighting of the room.

In a bedroom, the lighting is similar to that of living areas but can be less intense, with 100 to 200 lux being sufficient, or between 2,000 and 4,000 lumens. The main criterion for bedrooms is the light color (measured in kelvins), which should be warm white to promote sleep. Avoid bulbs with a color temperature above 3,500 kelvins, as they emit a blue light.

In a kitchen, opt for diffuse lighting for the ceiling light. However, a spotlight or wall light above the sink and countertop will need directional lighting with a narrow beam angle. Like work areas, strong lighting is often appreciated.

In a bathroom, directional spotlights are often ideal as they can illuminate specific areas (shower, mirror, etc.). The spots should be compatible with damp environments. Finally, a color close to daylight is recommended; choose a color temperature between 2,700K and 3,000K.