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How to Read Bulb Base Types (And Shop Online Like a Pro)

How to Read Bulb Base Types (And Shop Online Like a Pro)

You need new LED bulbs for your home, but because of the current situation due to Corona Virus, you decide to shop online rather than walk down to the local store — and rightly so. However, just as you are about to hit the ‘buy’ button, the little voice inside your head shouts… “Hey, how do you even know these LED bulbs will fit the fixtures you have in your home?”

And you stop right there, stare blankly at the screen, feeling as confused as an elephant in a kiddie pool.

You wonder, “What now? Must I go out with the old globe in hand to compare against?” 

Heck, no. You can count on our help. We’ll tell you everything you need to know about different bulb bases in plain, simple language, so that you can shop LED bulbs online like a pro.  

Every LED light bulb carries a unique code — a combination of letters and numbers —printed on its base, as well as on the packaging. By the end of this post, we promise you’ll be deciphering codes faster than Tom Hanks in the DaVinci Code and know exactly which LED light bulb goes with which fixture in your home.

So let’s dive right in.

Popular Types of Bases (or Caps)

The most common bases used in Australian homes are either screw (Edison screw) or bayonet. A niche type of base, called Glass Type Lamp (or simply G), is also becoming quite popular. Each of these three bases is available in range of sizes.

Edison Screw (denoted by the letter E)

Developed by the Thomas Edison himself, the Edison screw has a threaded metal base that screws into a matching socket.

Three most popular sizes for this base are as follows:


The E27 base is commonly referred as simply Edison Screw or just ES. The number ‘27’ here alludes to the diameter.

This is how the E27 base looks like.


This base is a common type of fitting for standard household light fittings. The E27 LED light bulbs are a replacement for bulbs usually seen in bedside lamps, desks or pendant style lights, and other old-styled lighting fixtures that use the incandescent bulbs.

For this reason, if you want LED bulbs for your existing fixtures, the E27 LED bulbs are just the one for you. They allow you to switch from incandescent to LED without any hassle.

We offer E27 bulbs in a range of styles so that you never have to pick between style and convenience.


The E14 is the most popular smaller version of the Edison screw and has a 14mm base. It is also known as Small Edison Screw (SES).

This is how the E14 looks like.


The Small Edison Screw (E14) LED bulbs are typically used in ceiling fans, novelty lighting, and certain lamps.

We offer E14 in a range of styles, shapes, and prices. Regardless of your needs and budget, we are sure you’ll find one that you love.


The E12, also known as Candelabra Edison Screw (CES), is generally used for nightlight bulbs. Sometimes, it is also used as decorative light bulbs in bathroom mirrors and chandeliers. The number ‘12’ here refers to the diameter.

This is how the E12 looks like.


Here are some cool E12 Edison Screw bulbs for your home. Check them out.

Bayonet Cap Base (denoted by the letter B)

This base comes with two ‘mounts’ on either side of the bulb that slips into L-shaped holes in the socket. The bayonet base is the most common base used in Australia.

The two most common types of bayonet base are as follows:


Also known as simply Bayonet Cap or BC, the B22 bulbs have the classic bayonet base fitting. The number ‘22’ refers to the diameter of the LED light bulb cap.

Like E27, the LED bulbs with the B22 base are commonly used for replacing bulbs typically seen in desks or pendant style lights, bedside lamps, and many other older style lighting fixtures that use incandescent bulbs. In short, you can use LED light bulbs with the B22 base to replace the traditional incandescent bulbs in your home. They look the same and fit into the same fixture.

Just keep in mind that while the LED bulb with the E27 base is a screw fit in, the bulb with the B22 socket secures into the socket by a twist-lock.

This is how the B22 looks like.


We offer LED bulbs with the B22 base in a range of styles and shapes. Have a look.  


The B15 base is known as Small Bayonet Cap or simply SBC. These LED bulbs are used for varied purposes, perhaps the most common being for candle bulbs for chandeliers.

Here’s how the B15 looks like.


Here are some cool B15 LED bulbs to add a modern, clean appeal to any space.

Glass Type Lamp (denoted by the letter G)

The two most common types of glass type lamp base are as follows:


Commonly used in RV lighting and under-cabinets, G4 LED light bulbs are ideal for small spaces and decorative fixtures. However, don’t be fooled by their small size, the LED bulbs with G4 base pack quiet a punch when it comes to performance. The number ‘4’ here stands for the 4mm gap between each pin.

Here’s how the G4 looks like.


Check out our best-selling G4 LED bulbs.


Best suited for decorative fixtures, G9 are compact in size and feature a bi-pin design. The number ‘9’ denotes the 9mm gap between the two pins. These bulbs are perfect for creating a cozy, relaxing ambience.

This how the G9 looks like.


Browse through our selection of dimmable G9 LED light bulbs.

Wrapping up

Picking the correct base type is important to ensure compatibility with a fixture. The unique code printed on packaging and at the base of every LED bulb sheds light on its base type. Thanks to this post, you will now be able to easily crack the LED light bulb —and shopping LED bulbs online will be a breeze.

Shop online. Stay Safe. Together we can beat the Corona virus. 

Frequently Asked Questions

  1. What are the different light bulb bases?

While there are a number of different base types, the two most commonly used in Australia are the Edison Screw (ES) and Bayonet Cap (BC).

  1. How do you read a light bulb code?

A light bulb code is a combination of letters and numbers. The first type tells you the base type and the second the diameter. For instance, the code E27 means the bulb has the Edison Screw base and the diameter of its base is 27mm.

  1. How do I know what base my light bulb is?

The two most common LED light bulb base types are the Edison Screw and Bayonet Cap. If the LED bulb has two ‘mounts’ on the either side of its base, it is a Bayonet Cap. On the other hand, if the LED bulb is a screw in fit, it is an Edison Screw.