How Much Light (Watts or Lumens) Does a Room Need?

How to fix a dark room, and it ain’t with paint…

While I am a paint color and home update expert, I’m NOT a rocket scientist. That being said, I don’t need to be a rocket scientist to know the following:

Dark rooms aren’t fixed with the right paint color but with the right lighting. End of story.

That’s right, my friends. If you don’t have the right lighting in your dark room, no magical paint color will save you—unless it’s glow-in-the-dark.

Let there be light!

Let’s get down to the nitty-gritty – how much light YOUR room needs…

(By the way, I’m not a lighting expert; I’m a paint color expert who does her best to understand this kind of stuff.)

THE MAGIC FORMULA

Multiply the room’s width by its length, then multiply it by 1.5 – this will give you the watts you need.

width x length x 1.5 = wattage

For example:
8w x 10l = 80 sq ft. 80 x 1.5 = dammit, where’s my calculator.  Right, 120.

So an 8 x 10 room needs 120 watts of light.

Technically, most small rooms (8×10 or smaller) can get away with 120 watts of lighting. However, getting enough wattage in a single light fixture can be challenging once you hit the bigger sizes. So what do you do?

Drink wine and cry. Just joking, you’ve got this.

You might also measure in LUMENS, in which case you’d want approximately 20 LUMENS PER SQUARE FOOT. Some say as low as 10 lumens, but that might not be enough for the function of some spaces.

The number of lumens you use can vary depending on how much light you need for the room’s task/function. 

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For example, in a bathroom, you might want a few more lumens vs. less. So, let’s say your bathroom is 5 x 8 = 40 sq ft. 40 x 20= 800 lumens. Based on the above graphic, that would mean you need 8 – 12w LED bulbs (which, back in the day, would be one 60w bulb). I’d want a bit more and would probably throw in two 6-9w bulbs or even two 8-12w bulbs. You do you, boo.

That’s a lot of numbers, I know. There are probably more straightforward websites, but again, I’m a color girl. If you’re in this for my charm and wit and questionable math skills, keep reading.

HOW MUCH LIGHT DOES A SMALL ROOM NEED?

Approx. 80 – 120 SQ FT 

Rooms in this size range need approximately 120-180 watts of light. For this reason, I’m inclined to adopt the ‘the more, the merrier’ approach; I would install a light that holds three 60W bulbs. However, general light fixtures don’t necessarily add ambiance, and you may still want to add some accent lighting (especially in a bedroom).

A SMALL ROOM WILL NEED…

• At least one light fixture that holds three – 60W bulbs or the equivalent wattage in pot lights.

• Two table lamps for ambiance.

Do you have a booby light that only holds one or two – 60w bulbs? Oh, you are so busted. If so, read this…Budget-Friendly Lighting Update Ideas

HOW MUCH LIGHT DOES A MEDIUM-SIZED ROOM NEED?

APPROX. 144 – 180 SQ FT

Rooms in this size range need approx. 215-275 watts of light. Unless it’s a dining room or a room that can hold a chandelier (usually five or more bulbs), you’ll need a central fixture and accent lighting to have it ‘well-lit.’

Don’t be afraid to lower your central/general light (as long as the bottom is at least seven feet from the floor). This can make a space feel brighter yet more intimate.

A MEDIUM-SIZE ROOM WILL NEED…

• ONE central light fixture that holds four to six – 60w bulbs.

• You could also add two table or accent lights that hold 40-60w each.

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HOW MUCH LIGHT DOES A LARGE ROOM NEED?

200 sq ft +

If you have a larger room with only one central light fixture (and don’t plan on hiring an electrician to add pot lights), you’ll need at least three table/floor/accent lights to make up the difference.

I BET this room doesn’t have enough light! 

Again, w x l x 1.5 = wattage

For example, a 12 x 18 (216 sq ft) x 1.5 room requires 324 watts. Now, you can get 180 of those via a central light fixture/pot lights; however, you will likely need to supplement with table lamps (60w each), which will get you closer to the mark.

Plus, table lamps and accent lighting add mood and ambiance to a space, so even if you DON’T need the extra wattage, I consider these pieces an essential part of any decorative arsenal, no matter WHAT size the room is.

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A LARGE ROOM WILL NEED…

• ONE central light fixture that holds a minimum of three – 60w bulbs (or pot lighting).

• THREE table/floor/accent lights that each hold 60-100w (the more, the better).

• If you have an open layout, like the room shown above, separate each space into functional areas. Measure those areas and then determine the wattage needed.

ROOMS THAT ARE LONGER THAN 20 FEET

If you have a room that’s LONGER than 20 feet, you may want to ‘visually’ cut it in half and then treat the two halves as separate rooms. This way, you can light each half of the room, which, as a whole, will create a ‘well-lit room.’

In this next room, with pot lights, two central hanging light fixtures, and table lamps, you can see how the room is split into two sections, making it look well-rounded and well-lit.

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This photo shows how recessed lighting and track lights can define social areas. In between pot lights, track lighting, and accent lighting – this room has it covered!

REMEMBER…

Many rooms require a central light or recessed lights, as the the primary source of lighting. These lights light the space whether all secondary/accent lights are on or off.

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If you don’t have a central light fixture (or pot lights), supplement with table and floor lamps that supply your room’s wattage (read below for more).

• Central or general lights are usually located in the center of the room.

• Many modern homes have recessed or pot lighting instead of a central or general light, which, when done correctly, can be as effective as a central light fixture.

• Every dark room or area (including hallways) should have a general light that holds at least three – 60w bulbs.

• Some designers have a hate-on for recessed lights (which is ridiculous to me – recessed lights can be great). You do you. While I don’t recommend going overboard, MANY main living areas benefit from well-planned recessed lighting.

EVERY ROOM SHOULD HAVE ACCENT LIGHTING

WHAT IS ACCENT LIGHTING?

Accent or task lighting may include table lamps, floor lamps, wall sconces, recessed/pot lights/under-cabinet lighting, etc. In a pinch, accent lighting with the right wattage will do the job when there isn’t a central light fixture.

Look at all of the accent lighting in this space – MAD LOVE! Benjamin Moore Edgecomb Gray

• Accent lighting highlights the features of your home, allows you to perform specific tasks (task lighting), and creates a sense of ambiance. Even if your central light is doing the job, accent lighting just adds to the room’s overall appeal.

• A white or off-white lampshade will shed a brighter light than a dark or colored lampshade.

• In the average room, you should have three accent lights that would create a triangle if you drew a line between them (as shown in the above photo)

Well, I hope you found this article en-LIGHT-ening (mwah-ha-ha).

READ MORE

The Best Light Paint Colours for a Dark Room

How to Choose the Right Light Bulb KELVINS for Your Paint Colour

How to Make a Dark Room Feel Brighter with Sheen

The Best Off-White Paint Colours

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ORIGINALLY WRITTEN FOR YOU IN 2018, AWESOMELY UPDATED IN 2025