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You might be clear on the difference between watts and lumens, but what’s a lux? Understanding this measurement could be key to getting the lighting effects you need for your property.

A Quick Reminder

• A watt is how much power a light uses.
• A lumen is the total light output of a light source.

Watts no longer accurately reflect how bright a light is, because LEDs are simply so efficient. Always check the lumens for a measure of how bright a specific light or bulb is.

It is, however, still important to check wattages so you don’t overload a circuit!

OK, So How Does This Relate To Lux?

Simply put, 1 lux is equal to 1 lumen spread out of an area of 1m². If lumens are a measure of brightness, think of lux as a measure of intensity.

So, 1000 lumens concentrated in an area of 1m² is equal to 100 lux.

If you are given a specification in lux, this tells you how many lumens you need in the given measured area.

Where Is Lux Used?

One of the most common uses of lux as a key measurement is in commercial lighting setups, where you need a certain amount of light spread over a given area to be suitably safe for employees and members of the public.

It can also be helpful for more domestic light design goals, particularly if you’re setting up areas of focused spotlights in kitchens and bathrooms, although in these cases precise numbers aren’t as necessary.

Some Real World Numbers

Here are some points of comparison, and the typical amount of lux required in different environments.

• Ambient daylight: 10,000-25,000 lux
• Moonlight: 1 lux
• A Family Living Room: 50 lux
• A Factory: 750 lux
• A Classroom: 250 lux
• Stairwells and other public corridors: 200 lux
• A supermarket: 750 lux.

For commercial environments where specialised tasks are performed, including certain indoor sports, technical drawing, mechanical work, and things that require sharp visuals, you could need anywhere between 1000-25,000 lux.

How Many Lumens?

Knowing the lux requirements for a room can help you figure out how many lumens you need. To perform this calculation, you’ll also need to know the area of your space.

Lumens Required = Area x Lux

Let’s take a classroom as an example. The average UK classroom is about 70m², and requires around 250 lux. That means you’d need a total of 17,500 lumens spread over the room.

If that sounds like a lot, don’t panic! LED lights can produce plenty of lumens for a much lower wattage requirement, meaning you can meet your lux needs without

Get in touch with us today and we can give you advice on finding the right lights for any space! Simply give us a call on 0116 321 4120, or send an email over to cs@wled.co.uk!

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