How to Identify Your Reflector Light Bulb

Feb 24, 12 How to Identify Your Reflector Light Bulb

Before CFLs and LEDs, most people referred to reflector light bulbs simply as “flood lights,” or even less correctly, as “halogens.” Only designers and commercial lighting installers knew bulb shape jargon like “PAR30″ and “BR40.”

For better or worse, that’s no longer the case. Since the advent of more energy-efficient lighting technologies, selecting a light bulb has actually gotten more complicated, often requiring everyday customers to know specialized bulb terms. No longer can you unscrew a burned out bulb, take it to the local hardware store, and pick the bulb’s exact match. Now you have to ask yourself not only “What is this?” but also “What replaces this?”

Fortunately, learning the terminology and selecting the right bulb is easier than you might think.

R-Type Bulbs (R20, R30, BR30, R40, BR40)

If you’re replacing a bulb inside your home with a diameter between 2-1/2 and 5 inches, you’re likely looking for an R-Type bulb. They’re what you usually see in kitchens, living rooms, and media rooms, especially in recessed cans. R-Type bulbs have a frosted face that evenly diffuses light and eliminates glare, but unlike a PAR bulb (explained next), the entire bulb envelope (lighting nerd speak for the outside of the bulb, not including the base) is made of blown glass. The outside of the bulb is completely smooth, and the bulb is relatively lightweight since it only consists of thin glass, a filament, and a brass base.

Because LED replacements for R-Type bulbs are rare and CFL replacements are much more easily found, let’s focus on CFLs: To identify the CFL replacement you need, select an R-Type bulb based on its diameter. All light bulb diameters are referred to in eighths on an inch, so if the diameter of your bulb is 20 eighths of an inch (2-1/2 inches), you’ll need an R20 CFL. If your bulb is 30 eighths of an inch in diameter (3-3/4 inches), you’ll need an R30 CFL, and so on.

PAR Bulbs (PAR20, PAR30, PAR38)

If you’re replacing a reflector bulb on the exterior of your home with a diameter between 2-1/2 and 4-3/4 inches, you’re most likely looking for a PAR bulb. Unlike R-Type bulbs, PAR bulbs feature an aluminum reflector with a special pattern of impressions that amplifies and concentrates light in a single area. The bulb envelope is made of two pieces: The glass face and the shiny aluminum wall of the envelope. The texture of the bulb will be either rough or textured and the bulb will be heavier than an R-Type bulb due to thicker glass construction. PAR bulbs are also used indoors, especially in track lights; in a pinch, they’ll work just fine for recessed lighting as well.

Both LED PAR bulbs and CFL PAR bulbs are easy to find, though they aren’t always weatherproof like traditional halogen PARs, so be sure to check their UL listing before installing them outdoors.  You can determine if you need a PAR20, PAR30, or PAR38 based on the bulb diameter in eighths of an inch, just as you would with an R-Type bulb.

An Exercise in Reflector Bulb Identification

A reflector bulb in your living room has just burned out. It’s in a recessed light. When you remove it, you notice that the sides are smooth and the bulb is surprisingly lightweight. When you measure the diameter, it comes out to 3-3/4 inches. What is it? If you guessed it’s an R30, you’re right. Now what do you replace it with? If you guessed a CFL R30 or an LED PAR30, you’re also right!

If you can’t identify your bulb, no worries! Feel free to describe it in the comments on our blog, post it on the 1000Bulbs.com Facebook wall, or ask us about it on Twitter using our handle @1000bulbs.


Benjamin is a writer for 1000Bulbs.com.

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  1. Bob Sauers /

    I found this article to be minimally useful. It would have been much more useful if you had explained the difference between R30 and BR30 bulbs. In addition, defining the “PAR” in PAR30 would have been helpful (parabolic reflector – in the shape of a parabola [remember high school algebra]. A PAR light bulb tends to narrow the beam more than an R light bulb does, but the light goes further — that’s why it’s good for outdoors.

    • Benjamin Rorie /

      Great points, Bob. It’s an introductory article, so I didn’t want to get too in depth.

      Since you brought it up, I didn’t know there is a difference between a BR- and an R-type lamp. I know the ER-type lamps are quite different, however. Care to elaborate on the differences?

      Thanks for the comment.

      • Phil Hord /

        The BR bulbs are bulged so they extend outside the can and enjoy light from the edges of the bulge.

  2. B J /

    Would like to know about beam spread and what to use to highlight product at what distance.

    • Benjamin Rorie /

      That sounds like a good topic for another article, BJ. I’ll add it to my list. But in the meanwhile, here’s a short answer:

      If you want to highlight something specific instead of lighting up a general area, you’ll need a bulb with a “spot” or “narrow spot” beam pattern. That translates to a beam angle of 15 degrees or less. In terms of distance, the “sweet spot” (where light output starts to drop off) is about 10 feet for PAR lamps.

      That’s a generalization, of course. Is there a specific application and bulb type you’re thinking of?

  3. Gordon /

    I have two questions:
    1. Is there an LED replacement for a Phillips Director 40W Bulb?
    2. The bulb (incandescent)in my porch light fixture burns out regularly. I have replaced it with a CFL but they don’t last much longer. The bulb is oriented in the horizontal position by the fixture. Can I use an LED as a replacement or would the beam be too directional?

    • Benjamin Rorie /

      Good questions, Gordon.

      1. No, there is not an exact LED replacement for director bulbs, though an LED R20 may work.

      2. You can absolutely use an LED bulb on your porch as long as it’s in a covered fixture. If it’s an A-shape LED, directionality shouldn’t be a problem. This Philips EnduraLED is a good option.

  4. I am trying to decide between Par30 and Par38 fixtures for my retail store, can you please advise why one might be better than the other if they are both 75watt Halogens. I will replace longterm with LED bulbs and I understand that I will get less wattage with a Par30, but in the meantime, using Halogen, is their a reason I should choose par 38 over par 30?

    • Thanks for reaching out to us! As far as we can tell, if the Par30 and Par38 are both 75 watts, the only difference will be the size and lumen output. Because the Par38 bulb is larger, it will produce brighter light. So, it really all depends on what you’re trying to light. If you are looking for brighter illumination, you may want to stick with the Par38 bulb. However, if the brightness of the bulb doesn’t matter, either will work. Hope this helps. Let us know if you have any further questions!

  5. Mary /

    Will BR30 – R30 indoor, incandescent flood lights be banned along with standard bulbs?

    • Thanks for the question, Mary!

      No, BR30 and R30 indoor incandescents will not be banned because they are reflector lamps. Reflectors are just one of the many types of incandescent bulbs not being affected by the new regulations. For a full list of exempt lamps, see Section 321 of the Energy Independence and Security Act of 2007 here: http://www.gpo.gov/fdsys/pkg/BILLS-110hr6enr/pdf/BILLS-110hr6enr.pdf. Please let us know if you have any further questions!

  6. nulle /

    currently using a regular 75w equiv CFL in recessed slot rated 75W R30. Can I replace the 75w equiv regular CFL with a 90w equiv R40 CFL?

    • Jordan Loa /

      Thanks for the question, Nulle!

      In your current setup, if you were using a 75-watt equal CFL R30, you could put in a 20-watt CFL R30, which is equal to 90 watts. However, chances are your current fixture won’t hold an R40 lamp because of the size difference in the diameters. I would recommend going with a higher wattage CFL R30. Hope this helps!

  7. Evan /

    Hi all… I found years ago that there were two different styles of r20 bulbs, the ones marked (perhaps unintuitively) “Director” create a relatively wide, diffused wash of light while those marked “Reflector” have a much tighter beam that works better for the room I have them in.
    I haven’t been able to find the Reflector style r20s for a long time now; does anyone have any thoughts?

    Thanks very much

    • Jordan Loa /

      Thanks for reaching out to us, Evan!

      First off, what kind of application are you using your current bulbs in?

      The director style R20 bulb you mention has a whiter face, which has a very wide beam spread, while the reflector style has a narrower beam spread. Fortunately, we do carry the reflector types you’re looking for: http://www.1000bulbs.com/search/?q=R20

      Let us know if you have any further questions!

  8. Evan /

    High hats in a living room… the narrower beam works better for highlighting the center of the room

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