Recessed Lighting Calculator: How Many Recessed Lights Do I Need?

See the light with this recessed lighting calculator

Photo: AleksandarNakic / E+ / Getty Images
Photo: AleksandarNakic / E+ / Getty Images
Highlights
  • Use the square footage of a room to determine how many recessed lights you need.

  • Install one recessed light for every 25 square feet of space.

  • Leave between 4 and 6 feet of space between lights, depending on the ceiling height.

  • Taller ceilings require more lights and extra spacing between them.

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Ready to revamp your lighting? Recessed lights let you illuminate your space in a discreet, minimalist way—but installing them requires a little bit of planning. And if you decide to map out your lighting layout yourself, one of your first questions will probably be: How many recessed lights do I need? Here’s how to figure it out.

How Many Recessed Lights Do You Need?

There are several factors to consider when deciding how many recessed lights you’ll need in a room, including the purpose of the lighting, the wattage of the bulbs, and the height and color of your ceiling. 

However, a good rule of thumb is to install lights 4 to 6 feet apart, with all lights positioned at least 2 feet from the walls. Based on that, here’s how many recessed lights you’d need for rooms of different sizes:

Room Dimensions (in Feet)Room Size (in Square Feet)Number of Recessed Lights Needed
10x101004-6
12x121444-6
12x182166-8
14x202808-10
20x2040012-14

Calculating the Number of Recessed Lights You Need

Drawing a layout of your room is the best way to figure out how many recessed lights you need. But first, you’ll have to figure out the right amount of spacing between lights, which you can do with this formula: 

Spacing Between Recessed Lights (in feet) = Ceiling height (in feet) / 2

How to Measure for Recessed Lighting

Whether you’re installing recessed lighting in your kitchen, living room, or another part of your home, your first step is to get the dimensions of the space. You’ll need three measurements: 

  • Length of the room

  • Width of the room

  • Height of the ceiling

Next, sketch out the layout of your room with a pencil and paper. It should include these dimensions, as well as the locations of any existing light fixtures or ceiling fans, furniture, and appliances.

Then, use the formula above to calculate the appropriate distance between lights. For example, if you have 10-foot ceilings, your lights should be 5 feet apart. Each light should also be 2 or 3 feet from the walls.

Finally, decide how you’d like to arrange the lights (for example, around the perimeter of the room or in parallel lines). Then, use the spacing guidelines to mark the locations of the lights on the map you drew of the room.

Who to Hire to Install Recessed Lighting

These guidelines can help you map out a design for your lighting. But when it’s time for installation, it’s safest to hand your plans over to a professional who can install recessed lighting. That’s because this job involves working with electricity, running new wiring, and cutting holes in your ceiling—all tasks that are better left to a local light fixture installation pro.

Frequently Asked Questions

For a 10-by-10-foot room, you’ll usually need between four and six recessed lights. However, this is a general figure because each space is different. In addition to your room’s square footage, it’s also important to consider other factors, like the purpose of the recessed lights. If they’ll serve as ambient lighting, you’ll need more lights than you would if you were using them for accent lighting.

On average, installing recessed lighting costs $100 to $300 per fixture. There are a few factors that influence these costs, including your ceiling’s material and the type of bulbs you choose. Labor prices in your area will also affect your project costs since professionals generally charge more in higher cost-of-living regions.

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