Understanding common household light bulb shapes, sizes, and styles is important whether you’re converting outdated incandescent fixtures into energy-efficient ones or using LED bulbs for new-construction applications. Every light bulb has identifying characteristics that are represented by a letter or series of letters and a number; these are known as light bulb codes. The letter or letters in a bulb code indicate either shape or special features such as reflector type. Numbers in a bulb code indicate size in millimeters or eighths of an inch. These codes will tell you if a bulb will fit in your fixture and if it’s the right shape.

For every light fixture or application, there’s going to be a specific bulb or light bulb shape that will fit best and provide the right type of light. If you understand bulb codes, it’s easy to look at a light fixture and know right away what kind of bulb you’ll need.

Let’s talk about light bulb groups, their bulb codes, and what applications those bulbs are typically used for.

Standard/arbitrary (A) bulbs are the most widely used and thought of when it comes to household lighting. These bulbs work well for a variety of applications, such as ceiling lights, lamps, vanity lights, kitchen lights, closet lights, porch light fixtures, and so many more.

Numbers in each code refer to the bulb’s diameter in one-eighths of an inch.

A15 bulb: 15/8 = 1-7/8″ diameter

A19 bulb: 19/8 = 2-3/8″ diameter

A21 bulb: 21/8 = 2-5/8″ diameter

A25 bulb: 25/8 = 3-1/8″ diameter

Most common base types:

Globe (G) bulbs have a full, round shape and are available in various sizes. They can be used for many applications throughout the home, such as foyer lights, kitchen lights, chandeliers, and ornamental fixtures. The most common type is the large G30 bulb, which is used in bathroom and makeup vanities.

Depending on the bulb, numbers in each code can refer to the bulb’s diameter in one-eighths of an inch or in millimeters.

G11 bulb: 11/8 = 1-3/8″ diameter

G14 bulb: 14/8 = 1-3/4″ diameter

G16/G50: 16/8 = 2″ diameter

G60: 60 millimeters = 2-3/8″ diameter

G25/G80: 80 millimeters = 3-9/64″ diameter

G30: 30/8 = 3-3/4″ diameter

Most common base types:

All of the bulbs in these groups resemble the shape of a candle flame and are often referred to as candle bulbs. Conical (C) bulbs are shaped like a cone. Conical angular (CA) bulbs are shaped like a cone but have a bent tip. Blunt-tip (B) bulbs are very similar to C-type bulbs but have more of a torpedo or bullet shape. These bulbs can be used in chandeliers, wall sconces, pendant lights, night lights, decorative light strands, holiday light strands, and other decorative home lighting applications.

Numbers in each code refer to the bulb’s diameter in one-eighths of an inch.

B10 bulb: 10/8 = 1-1/4″ diameter

CA10 bulb: 10/8 = 1-1/4″ diameter

C7 bulb: 7/8 = 7/8″ diameter

C9 bulb: 9/8 = 1-1/8″ diameter

C15 bulb: 15/8 = 1-7/8″ diameter

Most common base types:

BR stands for bulged reflector. Traditionally, the inside surface of an incandescent BR bulb is covered in reflector material that is used to gather and cast a wide beam of light away from the bulb. LED BR bulbs don’t require the reflector material. These bulbs can have a frosted, clear, or patterned dome-shaped lens that diffuses light and provides a gradual fade into nonilluminated areas. BR bulbs also produce less shadows when compared to PAR bulbs. They’re a bit longer than PAR bulbs and tend to protrude from light housings but are used in similar applications, such as track lights, recessed lights, display lights, or can lights.

BR20 bulbs are often referred to as R20 but have the same characteristics of other BR bulb types. The R stands for reflector.

Numbers in each code refer to the bulb’s diameter in one-eighths of an inch.

BR20/R20 bulb: 20/8 = 2-1/2″ diameter

BR30 bulb: 30/8 = 3-3/4″ diameter

BR40 bulb: 40/8 = 5″ diameter

Most common base type:

Multifaceted reflector (MR) bulbs are small in size with a reflective, faceted interior. The facets create a concentrated beam of light that can be displayed in a narrow spot or wide flood beam pattern. Because of the directional light they provide, MR LED bulbs don’t require the facets but often still have them. These bulbs are available in a variety of colors and can be used for many applications, including track lighting, recessed lighting, desk lights, and display case lighting. Many MR bulbs operate on low-voltage wiring systems, which makes them great for outdoor and landscape applications such as driveway lights, path lights, gazebo lights, paver lights, and malibu lights that have weatherproof housings.

Numbers in each code refer to the bulb’s diameter in one-eighths of an inch.

MR11 bulb: 11/8 = 1-3/8″ diameter

MR16 bulb: 16/8 = 2″ diameter

Most common base types:

Tubular (T) bulbs come in a variety of lengths and widths. Depending on their size, these bulbs can be used in applications ranging from chandeliers, wall sconces, and pendant lights to basement and garage troffer light fixtures.

Numbers in each code refer to the bulb’s diameter in one-eighths of an inch.

T7 bulb: 7/8 = 7/8″ diameter

T8 bulb: 8/8 = 1″ diameter

T10 bulb: 10/8 = 1-1/4″ diameter

T14 bulb: 14/8 = 1-3/4″ diameter

Most common base types:

Smart technology is poised to take over the home appliance market. We already have smart thermostats, smart lighting and even smart refrigerators. If that's not enough for you, there are some new contenders on the market that allow you to turn any electrical device in the home into a smart item. The best part is that it's a simple DIY experience – no need to find an electrician to hook it up. It’s the smart plug, a small box that you plug into your home's outlets. From there, you can use your smart phone to control whatever light, television or other electronic appliance routed through the smart plug. Read on to learn more about these remarkable efficiency devices.

Control and Monitor Your Electronics

There are a variety of smart plug options on the market: The Satechi IQ Plug, the Belkin WeMo Insight Switch, the D-Link Wi-Fi Smart Plug and the Valta Starter Kit, among others. The cost and functionality of the different brands vary, but they all operate on a similar principle – allowing you to set schedules and remotely control whatever device you choose.

The smart plugs connect to your phone via Bluetooth or wireless Internet, so you can switch them on or off from anywhere in the home – or even from the other side of the country if you have an internet-optimized model. You can also program schedules so the plug automatically activates an appliance at appointed times – turning a coffee maker on first thing in the morning, for example, or switching on a space heater before you go to bed in a chilly part of the house.

Retro Meets Modern

The upshot is that there's no need to wait for cutting-edge smart devices to come out to keep your home on the cutting edge of technology. Imagine impressing your neighbor by demonstrating the new smart functionality of a retro 1950s television, or your old Victrola vinyl player.

Smart plugs also monitor how much electricity a given device uses and when, so you can make informed choices about increasing your energy efficiency though disaggregation, breaking it down appliance by appliance. You can also save energy by using the smart plug to turn off the power to devices when you aren't actively using them, preventing your electricity bills from skyrocketing due to always-on settings or “energy vampires.”

Savings and Control All at Once

If you have additional questions about smart plugs and how they work, find an electrician who can show you their utility and functionality. With surprisingly little effort, you can harness their power to save energy and control devices all throughout your home.

“Hi. I’m Craig Bryant with Bryant Electric Service, and I’ve been in business in Austin for almost 30 years now. I’ve been asked by many people a lot of different things about electrical work, and so I hope I can help with answering some of your questions as well.

OK. I’ve been asked many times about the difference between aluminum and copper wire, and the biggest difference is that copper is just a lot more stable metal than aluminum. And electricity, the biggest enemy to electricity is heat. The hotter it gets, the more important it is to have a stable metal. Aluminum is good but not as good in that in the long run over many years or decades because the instability of aluminum, when it heats up it contracts and expands. As it cools down, it contracts and heats, it expands.

So that happening over time over years and decades especially at your main service or wall plugs or something then that causes a loose connection and it starts arcing and the arc can create a fire over time. That just doesn’t occur in copper ever if it’s installed properly and it’s real tight at the beginning when it’s installed.

So the other problem with aluminum is oxidation. As they’re both exposed to air, copper oxidizes as you can see when it turns green, but it doesn’t affect the connection of the wire. Whereas aluminum, when it oxidize, it creates this crust that builds on it. And you’ve probably seen it before, but this crust can sometimes get as much as a quarter inch thick. And besides the fact that the metal is not as compatible to the heat and temperature problem. With that crust building up, it will also create a gap between the connections that can cause an arcing.

So copper is always better than aluminum and everything except price. And the main reason that it’s being used is because it’s so much cheaper.”

Whether your home is old or new, there are probably some things you would like to change about it. While the layout and existing construction is often the first thing you think of, wouldn’t it be nice to make your work for you a bit more? If you have been dealing with a breaker that trips frequently or have to turn off everything in order to use a certain tool or appliance that is a bit of an energy hog, you could probably benefit from an electric panel upgrade. An electrician in Pasadena, like those at The Electric Connection, can help bring your home up to your electrical standards.

If your home is older (more than 50 years) it wouldn’t hurt to have an electrical inspection. During the inspection, the condition of your wiring will be evaluated to determine if your electrical problems may be due to faulty or deteriorating wires. You have to imagine 50 years ago, the average home had a handful of items that needed electricity. Today, almost every outlet in the house is in use with various computer cords, cell phone chargers and a long list of gadgets that make our lives easier.

Because of this, your Pasadena electrical needs are a little different and an electric panel upgrade will support all the gadgets you need and want without having to share outlets or unplug everything so you can use one appliance. In some cases, the panel itself may be just fine and you will just need an additional breaker installed. All of this can be determined after the electrician does the inspection and talks with you about what your needs are. From there, you can make a decision about what will work best for you. When you are ready or if you would like to learn more about an electric panel upgrade, give The Electric Connection a call today.