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Ultimate Guide to Light Globes and Bulbs

Choosing a light globe or bulb can be a very complicated affair these days. To make it easy, we have created an easy 5 step guide:
1. Choosing the TECHNOLOGY of your globe.
2. Choosing the BASE / SOCKET of your globe.
3. Choosing the BRIGHTNESS and WATTAGE of your globe.
4. Choosing the SHAPE of your globe.
5. Choosing the COLOUR TEMPERATURE of your globe

Choosing the technology of your globe

The following technologies are available to you:
LEDs (Light Emitting Diodes): these are the latest in lighting technology and are very energy efficient (80% less electricity than halogens), have very long life (25,000 hours), can be either dimmable and non-dimmable, and come in various colours.
CFLs (Compact Fluorescent Lights): energy saving (75% less energy than halogens), long life (8,000 to 15,000 hours), non-dimmable, and come in various colours.
Halogens: less energy efficient, shorter lifespan (2,000 hours), dimmable.
Edison filament globes: these are exposed globes used for decorative purposes or designer styles.
Incandescent globes: when we talk of globes, this is what most people think of - but in fact this is old technology that is incredibly inefficient and has a very short life (750 to 1,000 hours). These are actually being phased out. The Australian government has passed a law that is starting to ban most sales of incandescent globes.

Globe Running Cost Purchase Cost Life Efficiency Impact on Environment
Incandescent High Low 1,000-2,000 Low High
Halogen High Low 2,000-5,000 Low High
CFL Low Low-Medium 10,000-15,000 High Low
LED Low Medium-High 25,000-50,000 High Low

Choosing the base (or socket) of your globe

It goes without saying that the globe you select has to fit your light! So once the technology of the globe is selected, look at the manual or the box of your light - it will tell you what base (also called socket) the globe fits. There are a number of different types of bases, and within each type there are sub-types - ensure that you purchase a globe with the correct base as follows:

Bayonet Cap Light Bases

This is the common push and twist base with two locating lugs, and is found on most regular light bulbs.

B22 Bayonet light base
B22 Bayonet

BA15 Bayonet light base
BA15 Bayonet

BA9 Bayonet light base
BA9 Bayonet

Edison Screw Cap Light Base

The Edison bases are screw-ins, with the most popular socket (E27) having a 27mm diameter. The E14 Edison is commonly used for chandeliers and appliances.

E27 Screw light base
E27 Screw

E12 Screw light base
E12 Screw

E14 Screw light base
E14 Screw

E40 Screw light base
E40 Screw

Halogen Capsule Bases

Halogen capsule bases are designated by the number of millimeters between the pins. For example the G4 has pins 4mm apart.

G4 Halogen Capsule Base

GY6.35 Halogen Capsule Base

G9 Halogen Capsule Base

R7 Halogen Capsule Base

Downlight Bases

The most common downlights are push fit (GU4, GU5.3 or GU10). They come in various forms, including halogen and LED.

GU4 Downlight Base

GU5.3 Downlight Base

GU10 Downlight Base

Fluoresent Tube Bases

Fluorescent tubes normally have a two-pin fitting at the ends of the tube.

G5 Fluoresent Tube Bases

G13 Fluoresent Tube Bases

Choosing the brightness and wattage of your globe

Even though we have lumped brightness and wattage together in this section, they are completely different! In the old days, when incandescent globes ruled the day, wattage was directly proportional to brightness, and in fact people did (and still do) think of wattage and brightness as basically the same thing. However that's no longer true.


Wattage simply measures the power that the globe consumes. A LED globe of 10W can be much brighter than an incandescent globe of 60W. The one very critical thing to remember is that the globe you choose must not exceed the wattage of your light, as this can create a fire hazard. For example - if your light is rated for 20W do not get a globe that is more than 20W.


Brightness is not measured in watts but in lumens. The higher the lumens the brighter the light. As the vast majority of us still think of brightness in the old incandescent wattage scale, we have provided here for your benefit a table that will convert 'incandescent wattage' to brightness for various different types of globes:

Incandescent Globe (W) Halogen (W) CFLs (W) LED globes (W) Lumens (lm)
40W 28W 7-10W 4-5W 470lm
60W 42W 15-18W 6-8W 806lm
75W 52W 17-20W 7-12W 1055lm
100W 70W 20-25W 16-20W 1521lm
150W 105W 29-32W 25-28W 2452lm

How many lumens do I need?

To ensure you have the correct brightness for your room or furniture, here is an excellent guide we have prepared:

To Light Up Lumens Needed
Living Room 15 lm/sq foot
Kitchen Table 35 lm/sq foot
Kitchen Benches 75 lm/sq foot
Dining Room 35 lm/sq foot
Bedroom 15 lm/sq foot
Hallway 10 lm/sq foot
Bathroom 75 lm/sq foot
Tables in General 30 lm/sq foot
Desks in General 50 lm/sq foot
Floors in General 20 lm/sq foot

Choosing the shape of your globe

There are many shapes and sizes - as you can see below:

Globe shapes

Choosing the colour temperature of your globe

The very last thing you need to decide on is the colour temperature of your globe. It is not as important as the ones above, and many people don't bother - but it is worth thinking about. Colour temperature is discussed at length in another article on this website but to summarise, what you are looking for is as follows:

Colour temp