Bulb Sizes report
Since the traditional incandescent bulbs withdrew from the market and were replaced by energy-saving bulbs, the bulb market has undergone tremendous changes. There are many types of light bulbs to choose from, so many people feel confused and have headaches when buying light bulbs.
When it comes to the image of a typical light bulb, most people picture that one bulb many of us have been using all our childhood. It is the traditional A-type bulb. However, bulbs have been evolved significantly, and now you have them in numerous categories divided by shapes, sizes, and base types.
The respective parameters (shape, size, and base type) are marked on the package of the product. You will quickly get the correct bulbs once you learn about all the possible types. To help you choose the correct bulb, the following is a detailed bulb introduction for you, including common light bulb shapes, sizes, models, etc. Read on if you have ever been confused about the right bulb shape and size.
Bulb Shapes
Like identifying a base size, light bulbs use a letter-number reference to reflect the shape and size. The letter refers to the shape, and the number refers to the size. The main shape designations of light bulbs are:
- A – Standard household incandescent light bulb shape (widely used for home lighting);
- B – Bullet tip;
- BT – Bulged or Blown Tubular bulb shape (used for table lamps);
- BR – Short reflector style light bulb;
- C – Candle or Conical bulb shape (used for chandeliers and decorative lamps);
- E – Ellipsoidal bulb shape;
- ER – Extended reflector light bulb shape;
- F – Flame style candelabra bulb shape;
- G – Globe bulb or circular bulb;
- HK – Hexagonal Candle;
- K -Krypton or narrow reflector light bulb shape;
- MB – Halogen bulb;
- MR – Quartz reflector lamp (low wattage);
- PAR – Parabolic Aluminized Reflector (PAR) lamp;
- PS – Elongated standard incandescent bulb;
- R – Reflector light bulb style;
- S – Strait Sided bulb style;
- T – Tube lamp shape.
However, only three of all the bulb shapes are widely used for everyday purposes:
A-shaped Bulbs
A-shaped bulbs are standard types for household lighting, but you will see different variations and types of them. However, the standard bulb sizes are A19 and A60. The letter indicates the shape of the bulb, but the number following is the bulb's diameter in eighths of an inch. For instance, the A-19 bulb means that it is A-type, and the diameter would be 19/8″. For non-imperial measured bulbs, the number after the bulb shape is the centimeters at the widest point of the bulb.
B and C-shaped Bulbs
- B-shaped bulbs are also known as Candelabra bulbs. Bulbs with this shape have a bulged base that attenuates to a rounded tip.
- C-shaped bulbs look very similar to holiday lamps. The bulbs of this shape are very widespread in chandeliers, night lights, and lower wattage applications.
PAR-shaped Bulbs
PAR light bulbs use a parabolic mirror that focuses all the light. The most common PAR lamps are PAR20, PAR30, PAR38, and PAR42 types of bulbs. Those are just a few of the types available. These bulbs come in various beam angles, and they are widely used in spotlights and floodlights.
Bulb Sizes
Whether you are using identical bulbs to replace those that have burned out or upgrading to something more efficient or perhaps with a higher CRI, you need to choose the correct light bulb sizes. Every light bulb has to identify characteristics represented by a letter or series of letters and a number known as light bulb codes. Numbers in a bulb code indicate size in millimeters or eighths of an inch.
Diameter and length
As for the diameter and length, the categorization is a lot more simple. The main diameter classifications are:
8 = 1 inch;
11 = 1.375 inches;
16 = 2 inches;
20 = 2.5 inches;
30 = 3.75 inches;
38 = 4.75 inches.
A-shaped Bulbs Sizes
The code number of a bulb consists of a letter or letters followed by a number. The letter indicates the bulb shape, and the numbers in each code refer to the bulb's diameter in one-eighth of an inch. The most commonly used household bulb is the A-19.
| Bulb Code | Size | Diameter |
|---|---|---|
| A15 | 15/8 | 1-7/8″ |
| A19 | 19/8 | 2-3/8″ |
| A21 | 21/8 | 2-5/8″ |
| A25 | 25/8 | 3-1/8″ |
B and C-shaped Bulbs
The B- and C-shaped bulbs 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 similar to C-type ones 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. There are several common B- and C- bulb codes.
| Bulb Code | Size | Diameter |
|---|---|---|
| B10 | 10/8 | 1-1/4″ |
| CA10 | 10/8 | 1-1/4″ |
| C7 | 7/8 | 7/8″ |
| C9 | 9/8 | 1-1/8″ |
| C15 | 15/8 | 1-7/8″ |
G Bulbs Sizes
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.
| Bulb Code | Size | Diameter |
|---|---|---|
| G11 | 11/8 | 1-3/8″ |
| G14 | 14/8 | 1-3/4″ |
| G16/G50 | 16/8 | 2″ |
| G60 | 60 millimeters | 2-3/8″ |
| G25/G80 | 80 millimeters | 3-9/64″ |
| G30 | 30/8 | 3-3/4″ |
BR Bulbs Sizes
BR20 bulbs are often referred to as R20 but have the same characteristics of other BR bulb types. The R stands for reflector.
- BR20/R20 bulb: 20/8 = 2-1/2″ diameter
- BR30 bulb: 30/8 = 3-3/4″ diameter
- BR40 bulb: 40/8 = 5″ diameter
PAR Bulbs Sizes
PAR bulbs are commonly found in outdoor emergency light, spotlight, or floodlight fixtures but can also be used indoors for the track, recessed, display, or can lights. You can find the common PAR bulb sizes below. The numbers after “AR” refer to the bulb’s diameter in millimeters.
| Bulb Code | Size | Diameter |
|---|---|---|
| PAR16 | 16/8 | 2″ |
| PAR20 | 20/8 | 2-1/2″ |
| PAR30 | 30/8 | 3-3/4″ |
| PAR36/AR111 | 36/8 | 4-1/2″ |
| PAR38 | 38/8 | 4-3/4″ |
MR Bulbs Sizes
Multifaceted reflector (MR) bulbs are small in size with a reflective, faceted interior. These bulbs are available in various colors and can be used for many applications, including track lighting, recessed lighting, desk lights, and display case lighting. The most common sizes are MR11 and MR16.
- MR11 bulb: 11/8 = 1-3/8″ diameter
- MR16 bulb: 16/8 = 2″ diameter
