Light Bulb Shape Guide: BR & R Shapes

Home security light fixture which uses BR light bulbs or R light bulbs.

Updated 10/11/23 by 1000Bulbs Staff

Now that we've covered some of the smaller light bulbs commonly used in household lighting (A-shape, MR shape, Globes, and Chandeliers), it's time to move on to larger bulbs.

BR and R-shaped bulbs are directional light bulbs which focus their light outward. The most common uses for both shapes are flood lights, track lighting, or recessed lighting.

What are BR and R Shaped Bulbs?

R+Shape+Comparison NEW.jpg — R shaped bulbs caparison, including R16, R20, R30, and R40 light bulbs.

R Shaped Light Bulbs

The type and size of your light bulb can be determined by the bulb code, made up of 1-3 letters followed by a number. Reflector bulbs are indicated by a standalone “R.” These bulbs have a mirror-like coating of reflective material on the inside of the bulb's glass housing, boosting the light output.

BR Shaped Light Bulbs

BR bulbs are descendants of the R-shape bulb and therefore are very similarly shaped.

However, the “Bulged Reflector” bulb (abbreviated as “BR”) includes an extra reflector in the neck of the light bulb to better capture and direct light forward which is lost in the neck and sides of the standard R bulb. This extra reflector in the bulged reflector light bulb creates a “bulge” just before the socket base begins.

BR bulbs are used for everything from floodlights like the BR40 or IR heat lamps like the BR38. Most BR bulbs have bulging neck with the exception of LEDs and CFL bulbs like this BR20. — The differences in BR20, BR30, BR38, and BR40 bulbs.

BR bulbs are used for everything from floodlights like the BR40 or IR heat lamps like the BR38. Most BR bulbs have bulging necks with the exception of LEDs and CFL bulbs like this BR20.

Often BR shaped, heat lamp bulbs are used to keep food warm in commercial restaurants.

Finding the Right Size and Voltage for R and BR Light Bulbs

Once you know whether your light bulb is an R-shape or a BR-shape, then the numerical part of the shape code represents the widest part of the bulb's diameter measured in eighths of an inch.

If you divide the number in the light bulb codes by 8, the resulting answer is the diameter of your bulb in inches. The following chart covers the most common BR and R bulb shapes and their respective diameters.

Chart showing diameter in inches of the most common BR and R shaped bulbs.

After you figure out the correct bulb size, be sure to check the voltage rating before buying a replacement bulb for your fixtures. An incorrect voltage rating could result in the bulb shorting out. BR and R shape bulbs typically function between 120 to 130 volts.

Where Can I Use BR Shaped and R Shaped Light Bulbs?

Essentially, BR and R shape bulbs are directional flood lights, meaning the light is dispersed across a fairly wide area.

A BR or R shape bulb diffuses light, creating a softer edge than Parabolic Aluminized Reflector or PAR lamps. PAR light bulbs produce a concentrated beam of light (to be covered later).

The beam angle is typically 120 degrees for both R and BR lights.

You are more likely to find a slightly narrower beam angle for the smaller, R20 and BR20 bulbs, while R30 and BR30 bulbs could be broadly designated as spot or flood lights.

With large beam angles, BR and R shape light bulbs do well in situations requiring wall washing or wall grazing, as track lights for large areas or artwork, or providing general ambient lighting via recessed cans.

If you need a long-necked bulb for deeply recessed lighting, you can consider using the little-known ER30 or “Elliptical Reflector” bulb for your fixtures.

LED Options for BR and R shape Light Bulbs

BR and R shape light bulbs exist as incandescent bulbs (like these), CFL, or LED lights (like these).

Due to the heat sink design and the already directional nature of LEDs, BR LED bulbs and R shape LED bulbs are more of an aesthetic choice than a functional necessity. However, LED bulbs are known for their energy efficiency.

The light produced by BR LED bulbs is ideal for recessed lights or track lights, where a wide flood of light is needed, unlike LED PAR bulbs, which are known for producing a more focused light.

If you'd like to experiment with color temperature, BR shape LED bulbs provide several options, including the ability to choose a bulb that has the right color temperature for accent lighting in your space.

Choose a 2400K (Kelvin) bulb for a warmer, cozy light that mimics traditional incandescent bulbs. For a bright, cool light that is ideal for task lighting and reducing eye strain, choose a cool white 4000K bulb.

Some BR shape LED lighting options even have warm dimming capabilities, which can dim light output as well as change the color temperature to mimic the warmth of the sunrise and sunset.

For ambient lighting, LED BR lamps work well for hallways, offices, and kitchens, or even as foyer lights.

Shop 1000bulbs.com for BR Bulbs, Parabolic Aluminized Reflector (PAR) Light Bulbs and All Other Lighting Needs

Know some fun facts about LED BR bulbs? Did you know BR bulb abbreviated spells “BRB” or “Be right back”? Do you have a theory about why BR lights are always leaving? Write your comments, suggestions, or questions in the area below.

For help choosing the right bulb or decorative fixtures for your next outdoor lighting project, contact one of our knowledgeable US-based account managers, call 1-800-624-4488 or try our convenient “pop-up chat feature” at the bottom right corner of our 1000bulbs.com web pages.

The 1000Bulbs staff sadly announces that, despite many hours of testing, light bulbs do not work as lures to catch the ever-elusive Pikachu and his electricity-loving friends. On the plus side, at least you will be able to see the game.