The amount of light needed in a room depends on the type of room and the activities going on at a particular time. An office or library will require more light compared to a living room. Reading needs brighter lighting compared to watching TV.
We measure how much light an area receives using a unit called lux. It’s a measure of how bright a space is and can range from less than 1 lux (similar to a moonlit night) to 100,000 lux or more (resembling a bright summer day).
Here’s a guide on how much lux should be in a room.
Why Lux Matters
It’s not enough to have lighting in a room; the brightness of the light matters a great deal, too. You may not realise this until you try to do a visually intensive task like reading or drawing. If the light isn’t bright enough, your eyes will strain and you could end up with a headache or dry eyes.
Here’s why having the right amount of lux in a room is important.
- It increases visibility and reduces eye strain. You’ll be comfortable and more productive.
- It’s important for concentration when you are reading, studying, or doing any important task. Sufficiently bright lighting makes it easier to concentrate for prolonged periods without getting tired.
- In certain environments like hospitals and factory floors, sufficient lux is crucial for safety. There are standards that specify the suitable lux range for commercial and industrial spaces.
- The amount of light in a room affects your overall well being. Even if you are not reading or working, having enough lighting keeps your mood and energy up, especially during winter when we are all battling winter blues. But it’s not always about having bright light. At night, lower brightness is crucial for winding down.
Factors Determining How Much Lux Should Be In a Room
The right amount of lux varies widely depending on a number of factors.
Type of Room
At home, the kitchen will typically be the brightest lit room in the house, with ideal lux levels ranging between 300 and 750 lux depending on kitchen size and design. Having plenty of lighting in the kitchen is important both for comfort and safety.
For the living room and bedrooms, the ideal range is 50 to 300 lux is enough for general activities as well as more focused tasks like reading. Bathrooms need brighter lighting at between 300 and 500 lux, the same as a home office or a reading area.
Hallways and stairways should be lit by 50 to 200 lux lighting, with stair landings needing 150-200 lux of lighting to ensure safety.
As for office environments, the BS EN 12464-1 European Standard recommends 300 to 1000 lux lighting, depending on the specific area and the kind of work being done. 300 lux is sufficient for the reception area, while a work desk would need 500-750 lux.
Type of Activities
The more focused an activity is, the higher the lux required for focus and comfort. In spaces where people are just moving about, 50-100 lux is usually enough, which is why hallways don’t need to be super bright.
For casual reading, 250-300 lux is adequate, while more focused study requires 300-500x. Precision work, such as studying architectural drawings or medical tasks, needs lighting between 700 and 1000 lux.
Room Size
Two differently sized rooms can have the same type of lighting, but the smaller one will be brighter. The size of the room, including ceiling height, greatly affects how much lux is in the space. The bigger the room, the more lux you need to get enough brightness.
As we’ll discuss shortly, this is why it’s important to have both general and task level lighting instead of relying on one type of lighting for all activities.
Room Design
The dominant colour in a room affects how much light falls on surfaces. Darker colours like black, grey, and brown absorb more light and reflect less of it, while white and bright colored rooms will have higher lux even with the same lighting.
So if you have a room that has a darker colour scheme, you’ll need more lighting to get sufficient lux.
Other aspects of a room’s design that can increase or lower lux include shape (irregularly shaped rooms can create shadows), window size and placement, and furniture placement.
General and Task Lux Levels
In many cases, overhead lighting on its own is not enough to provide adequate lux for all activities that will take place in the room. Your living room light might be good enough for eating and relaxing, but not bright enough for reading.
The best lighting design combines general and task level lighting. General overhead lighting is suitable for non-focused activities and can usually be less than 300 lux. Task level lighting, provided by area lights like a desk lamp or under-cabinet lights, provides more lux for activities like reading, studying, and cooking.
How To Measure Lux
If you want to know the specific amount of light in an area, you can use a lux or light meter. We recommend using an incident light meter as it’s more accurate compared to a reflective meter. Here’s a video that goes into deep detail about lux meters and how to use them.
Final Thoughts
You don’t have to use a lux meter to tell whether a room is sufficiently lit. If your eyes strain when you are doing an activity, then you probably need to make the room brighter. You can make the overhead light brighter or get an area light.
