Bulb Types & Shapes Explained
It can all sound a bit confusing looking at lots of letters and numbers while having no idea what they actually mean. We have been asked recently why the letter and numbers so let's help explain the jargon.
Light bulbs have identifying characteristics, which make them unique from other bulbs. These characteristics are represented by a letter and a number, which are known as light bulb codes.
The code number of a bulb consists of a letter followed by a number.
The letter indicates the shape of the bulb
- A (Arbitrary) Most closely resembles a standard household bulb.
- G (Globe) Round or circular shape.
- S (Sign) Sometimes called straight-sided, they were traditionally used in signs.
- ST (Straight Tapered) This shape is most often seen in vintage, Edison-style bulbs.
The number relates to the diameter of the bulb in eighths of a millimeter
A19 and A60 Bulbs
Pear Shaped Bulbs
The A-Bulb series is the most classic and common of them all. It is the traditional edison style shape that hasn't changed since 1879! You'll find this bulb a lot within homes and commercial venues.
- A19 measures 110mm x 60mm
- A60 measures 100mm x 60mm
G40, G45 & G80 Bulbs
The G-Bulb which is more of a round shape.
- G40 plum shape
- G45 peach shape
- G80 orange shape
G-Type bulbs, or globe lights, are commonly seen in commercial venues, especially for bar and restaurant lgihting. Ranging in size from 40mm to 45mm and up to 110mm they can be as small as a golf ball and as large as an orange!
- G40 measures 40mm x 40mm
- G45 measures 45mm x 75mm
- G80 measures 118mm x 80mm
S14 & ST58 Bulbs
S-Type bulbs feature a distinctive tear drop shape and their bases.
- S14 is the shape of a teardrop
- ST58 is the larger teardrop.
You don't need to understand the light bulb jargon. Simply decide which style of bulb you like best!
The numbers and letters are for us experts to identify and code the bulb. Plus we think it sounds better to call it the G45 bulb rather than the "peach bulb."