Jun 262012

blogpost recessedlights1 How To Choose Light Bulbs For Your Home: Recessed Cans

This is the second post in a series dedicated to helping you create a home with beautiful lighting by choosing the best light bulbs. Yesterday, we tackled light bulbs for table and floor lamps. Recessed lights are a little more complicated, but once you’ve got the basics down, it’s smooth sailing!

The first thing you’ll need to do is determine which light bulb size your recessed light fixture takes. Here’s what you’ll see among recessed lighting options: BR30, MR11, MR16, PAR16, PAR20, PAR30, PAR38, R20, R30, R40.

Wow. Let’s break that down a little:

The number following the letters in a recessed light bulb indicates size: it’s the diameter of the light bulb in eights of an inch. So, a BR30 is 30/8 inches, or three and 3/4 inches. An MR11 is 11/8 inches. So, you can swap out a PAR30 for an R30 or a BR30 – they are all the same size.

The PAR denotes the light bulb has a parabolic aluminized reflector on its inside, directing light out. That PAR coating maximizes the light output that you’ll get from the light bulb. If brightness is your #1 priority in a recessed light, choose a PAR lamp in the appropriate size. The majority of PAR lamps are available in a flood beam spread, but spot beam PAR lamps are also out there. Many PAR lamps are approved for use in wet locations.

The MR indicates the light bulb has a multifaceted reflector on its inside. The facets help gather light from the filament to create a very concentrated light beam. MR lamps are primarily available in smaller sizes – they are all about beam control, which is typically desirable for a narrower light beam. You can choose your beam spread (i.e., narrow flood, flood, spotlight) for many MR lamps.

Moving on to BR: Want to take a guess on what it stands for? This is another reflector lamp to maximize brightness, but this time, the light bulb itself has a bulged shape to direct light out. One disadvantage of the BR lamp is that it’s a little longer than the PAR and MR, which means it tends to sit lower in the recessed fixture – and perhaps, protrude from the bottom of the recessed light fixture.

Finally, the simple R. As you might assume, it stands for reflector in this case. There is a mirrored coating on the back of the light bulb to improve light output.

Now that we have those light bulb names deciphered, you should know that they are available in an array of light sources, including incandescent, halogen, compact fluorescent, cold cathode fluorescent, and LED. Halogen is probably the most popular of the bunch for recessed light fixtures. It renders colors very well, it’s affordable, and it gives you a lot of light output.

If you’re looking for efficiency, though, halogen is not your target. LED has a higher price point, but it also gives you a longer lifetime and lower energy use! Check out our selection of PAR, MR, and BR LED light bulbs.

CFLs and CCFLs are also viable energy efficient options, but remember you should avoid the CFL if the gradual start-up drives you crazy – or if you plan to turn the lights on and off frequently. (You’ll lower the lifetime of a CFL if you use it in less than 15 minute intervals). CCFLs give you the efficiency of a CFL without the delayed start-up (or the diminished lifetime from frequent power cycles).

More questions? The comment section awaits!


Emily WidleEmily graduated from UNC Chapel Hill with a degree in journalism. She enjoys scouring the news to report on the latest in the lighting industry as well as bringing valuable remodeling tips and exemplar home projects to light.

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  12 Responses to “How To Choose Light Bulbs For Your Home: Recessed Cans”

  1. I have bought BR30 in the Home Deport and the bulb doesn’t fit in out fixtures. It’s getting stuck, because the diameter was too big. I have always used R30, but had to return this one. Now I am not sure if that was a manufacturer’s defect or BR30 and/or PAR30 are different from R30.

    • Mikki,
      Thanks for your question! BR30, R30, and PAR30 light bulbs all have the same diameter (30/8 inches). However, they use different kinds of reflectors which cause them to have slightly different shapes PLUS the neck lengths for each light bulb can vary. That’s probably why that BR30 didn’t fit. In general, R30 lamps tend to be a little shorter.

  2. What is GU? I ordered recessed lighting that says they use GU10. 50w bulbs? What kind of lighting is that?

  3. We were remodeling our home and wanted brighter light than that produced by our 65W R30 light bulbs in recessed 6 inch cans. Our contractor recommended we buy LED, R30L (long neck), 13W (65W equivalent) bulbs with a light color of 6000K degees (daylight). Very expensive bulbs. Then, the contractor changed out our 6 inch recessed cans for 4 inch cans to “modernize” the look of our lighting. Now, I am being told the 4 inch cans require R20 or PAR20 size bulbs. Are you aware of any kind of 4 inch recessed can that can accept R30 bulbs? Or, is there any kind of conversion kit for 4 inch cans to receive the R30 bulb?

    Thank you for your help,

    • David:

      The 30 in the R30 represent 30/8 inches in diameter. So, an R30 is 3 3/8 inches in diameter. Too big for a 4-inch recessed can. A PAR20 (20/8 inches in diameter or 2 1/2 inches) is a common lamp for a 4-inch can.

  4. Hello,

    I have a question for different parts of my home, In the kitchen, I have four R40 bulb in the center and six R30 bulbs around the edges. I want it bright without shadows. I was thinking of LED 18W in like a PAR? What do you think? I have 9′ ceilings
    Then I have an outside porch with eight R30 bulbs, I want a softer but bright LED replacement, I currently have 60W bulbs, I would like it a tad brighter but keep it softer


    • John,

      Generally it’s OK to switch from R shaped light bulbs to PAR shaped in recessed lights. However, some recessed lights provide better coverage depending on the type you use.

      For example, in my home I’ve found that BR30 light bulbs are brighter because PAR30 lamps are too short and do not stick down far enough. I also prefer the very wide beam angle of flood BR light bulbs versus flood PAR lamps.

      I would suggest removing a light bulb and looking inside to see if there is a label advising what type to use. If that doesn’t work, then experiment and try different light bulbs.

      I’m not sure what you mean by a brighter but softer option for your outside porch. To me softer means less bright. Can you please clarify? It might be a challenge to find a quality LED replacement emitting more light than a 60W incandescent.

  5. I have new 4 inch recessed lights in my kitchen and living room….when I went to purchase bulbs, I was told that I need R20 size bulbs. The ceiling in the living room is vaulted and in the kitchen I would like bright white light to work in so I looked for halogen bulbs. At the store I was told that the halogen bulbs were too short and I would need an extension piece to be able to use halogen. I cannot find any information about extensions. Any advice?? Please let me know. Thanks in advance.

    • Bernadette:

      Without knowing exactly what your 4-inch recessed trim is shaped like I can only give you some general advice. I hope that this helps.

      I also have 4-inch recessed lights in my home. I use halogen PAR20 lamps for the same reason you wanted halogen. Plus, I did not want my lamp to show outside of my trim. R20 lamps are a reflector lamp and they have a slight bulge at the lighted end of the lamp. PAR20 is a parabolic reflector lamp and the lighted end of the lamp is flat. The 20 means that the lamp diameter is 20/8 inches. If you want halogen, I think the PAR20 lamp should work. I think that the store you were at might have been confusing 6-inch recessed (more common) and 4-inch recessed lighting. In some 6-inch recessed trims if someone wants to use a halogen PAR lamp they might need to get a long-neck PAR38 lamp. A PAR20 lamp does not have a long-neck version.

  6. We switched our old can lights because the old br30 stuck out of the trim and they were not adjustable. The new lights (5 inch) have a black waffle and require a par30 75 watt bulb. We have been unable to find a bulb that will fit, even a short neck (it was about 3.4 inches) the baffle stops it from screwing in. Any ideas?

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