Lumen (lm) is the unit used to measure the amount of light emitted by a light source. It's an important measure of light output and indicates how much visible light a lamp or other light source produces. The higher the lumens, the brighter the light.
What is Lumen?
Lumens don't measure a lamp's brightness , but rather the total amount of visible light it emits. In other words, they indicate how much light is emitted from the lamp in all directions, regardless of whether it's directed at a specific surface or diffused throughout the room. This makes lumens a useful metric for determining whether a lamp provides sufficient light for a specific room or application.
Lumen vs. Watt
With traditional incandescent bulbs, wattage (e.g., 60W, 100W) was often used to indicate a bulb's brightness. However, wattage measures how much energy a bulb uses, not the amount of light it produces.
With the advent of LED lighting, understanding lumens has become more important. LED bulbs consume significantly less energy than traditional incandescent bulbs for the same lumens. So, for example, a 9-watt LED bulb can produce the same amount of light (lumens) as a traditional 60-watt incandescent bulb, but uses significantly less energy.
How many lumens do you need?
The number of lumens you need depends on the size of the room and the desired light intensity. Here are some general guidelines for different rooms:
- Bedroom : Between 100 and 300 lumens per square meter. This is often sufficient for a soft, relaxing atmosphere.
- Living room : Between 150-300 lumens per square meter, depending on the size of the room and the desired brightness.
- Kitchen : Between 300-500 lumens per square meter. Since the kitchen is a functional space, you usually need brighter light for cooking and other activities.
- Bathroom : Between 300-500 lumens per square meter. Bathrooms require bright light for personal care.
- Workspace/office : Between 300-500 lumens per square meter for a good working environment.
Examples of Lumen values:
- A 25 watt incandescent bulb produces approximately 200-250 lumens .
- A 60 watt incandescent bulb produces approximately 800 lumens .
- A 100 watt incandescent bulb produces approximately 1600 lumens .
- A 12-watt LED bulb can produce 800 lumens , which is equivalent to a traditional 60-watt incandescent bulb , but with much less energy consumption.
Why is Lumen important?
Lumen is important for choosing the right lighting because it helps you understand how bright a bulb is and how much light it will emit. It's an objective measure of a bulb's light output , allowing you to better determine whether a particular type of bulb is suitable for your space and needs. For example, when choosing LED bulbs, it's helpful to consider lumens instead of wattage, as this allows you to get the lighting you need without using too much energy.
Summary
A lumen is the unit used to measure the amount of light emitted by a lamp. The higher the lumens, the brighter the light. Unlike wattage, which measures a lamp's energy consumption, lumens provide a better indication of its actual light output . It helps you determine how much lighting you need for a given space and ensures you're using the available energy efficiently.