The Ultimate PAR Light Bulb Size Chart: Your Comprehensive Guide for Easy Reference

Are you baffled by the vast array of light bulb shapes and sizes in the market? Light bulbs, particularly PAR (parabolic aluminized reflector) bulbs, come in diverse sizes such as PAR16, PAR20, and so on.

This article unveils an ultimate chart that simplifies these complex codes into a comprehensive guide; helping you swiftly navigate through this confusing terrain for your DIY projects.

Stay put, because we’re about to turn on a light!

Key Takeaways

  • Light bulb sizes can be confusing, especially for PAR bulbs. This guide simplifies the complex codes into a comprehensive chart to help you choose the right size for your DIY projects.
  • Common light bulb shapes and sizes include A19, MR16, and PAR bulbs such as PAR16, PAR20, PAR30, PAR36, and PAR38.
  • Understanding base sizes is important when selecting light bulbs. Common base sizes include medium (E26), candelabra (E12), intermediate (E17), bi-pin (GU10/GX5.3/G8.6), and recessed double contact (R7s/RSC).
  • The four main types of light bulbs are incandescent, halogen fluorescent, and LED. Each type has its own features and benefits that should be considered when choosing the right bulb for your needs.

Understanding Light Bulb Shapes and Sizes

Light bulb shapes and sizes can vary, depending on the specific type of bulb you are looking for. Some common examples include A19, MR16, and PAR bulbs in various sizes such as PAR16, PAR20, PAR30, PAR36, and PAR38.

There are also linear fluorescent bulbs like T5, T8, and T12.


A19 is a common light bulb shape you might see at home. The “A” stands for “Arbitrary.” It’s a fancy word for the pear-like shape of the bulb. The number 19 tells you how big it is across.

For an A19, it measures 2.375 inches in size or about as wide as a soda can! You get to use these bulbs in many places like table lamps, ceiling fans, and wall sconces. They are easy to find and come in lots of types like LED and fluorescent.


An MR16 bulb is a type of halogen light bulb that is commonly used in track lighting and accent lighting. It has a diameter of 2 inches (50mm) and uses a GU5.3 base size. The “MR” stands for “multifaceted reflector,” which refers to the mirrored coating inside the bulb that helps direct the light in a specific direction.

MR16 bulbs are known for their focused beam angles, making them ideal for highlighting artworks or creating dramatic lighting effects. They are available in different wattages and can be dimmable, allowing you to adjust the brightness to suit your needs.

LED versions of MR16 bulbs are also available, offering energy efficiency and longer lifespan compared to traditional halogen bulbs.

PAR16, PAR20, PAR30, PAR36, PAR38

These are various sizes of PAR (parabolic aluminized reflector) light bulbs commonly used in residential and commercial applications. The number following the “PAR” corresponds to the diameter of the bulb in eighths of an inch.

Light Bulb Type Diameter (in eighths of an inch) Common Applications
PAR16 2 inches Display lighting, accent lighting
PAR20 2.5 inches Recessed lighting, track lighting
PAR30 3.75 inches General lighting, outdoor lighting
PAR36 4.5 inches Landscape lighting, automotive headlights
PAR38 4.75 inches Outdoor flood lights, recessed lighting

Remember, LED PAR bulbs are becoming increasingly popular because they offer bright, dimmable light while consuming less energy. Their varied sizes, from PAR16 to PAR38, mean they can be adapted to a wide range of lighting needs. Understanding these sizes will enable you to choose the correct bulb for your specific application.

Linear fluorescent (T5, T8, T12)

Linear fluorescent bulbs, such as T5, T8, and T12, are commonly used in commercial settings. These bulbs have a long tube shape and are known for their energy efficiency. The numbers that follow the “T” represent the diameter of the bulb in eighths of an inch. So, for example, a T8 bulb has a diameter of 1 inch (8 eighths). Linear fluorescent bulbs require ballasts to operate properly and provide bright lighting. They are often used in offices, schools, hospitals, and other large spaces where task lighting is needed.

Light Bulb Base Sizes

Common base sizes are an important factor to consider when choosing the right light bulb for your needs. Read on to discover the different types of bases and how they can impact your lighting choices.

Common base sizes

Light bulb bases come in different sizes to fit various fixtures and lamps. Here are some common base sizes you should know:

  1. Medium (E26): This is the most common base size in the United States. It fits standard household lamps and fixtures.
  2. Candelabra (E12): This smaller base size is typically found in decorative lighting, such as chandeliers or wall sconces.
  3. Intermediate (E17): This base size is slightly larger than the candelabra base and is used in some specialty lighting fixtures.
  4. Bi-pin (GU10/GX5.3/G8.6): This base size is commonly used for low-voltage halogen bulbs.
  5. Recessed Double Contact (R7s/RSC): This base size is found in linear fluorescent bulbs commonly used in recessed lighting fixtures.

Types of Light Bulbs

There are four main types of light bulbs: incandescent, halogen, fluorescent, and LED.


Incandescent light bulbs are the traditional ones that have been used for decades. They produce light by heating a filament inside the bulb until it glows. These bulbs come in different shapes and sizes, such as A19, which is the most common type used in households.

Incandescent bulbs are known for their warm and soft light, but they are not very energy-efficient compared to other types like LED or fluorescent bulbs. It’s important to consider the wattage and color temperature of incandescent bulbs when choosing one for your lighting needs.


Halogen light bulbs are another type commonly used in residential and commercial settings. These bulbs provide a bright, white light that closely resembles natural daylight. Halogen bulbs are known for their high color rendering index (CRI), which means they can accurately reproduce colors.

They also have a long lifespan compared to traditional incandescent bulbs. Halogens come in various shapes and sizes, including A19 and PAR varieties. They can be used for general lighting purposes or in specialized fixtures like track lights and recessed cans.

When choosing a halogen bulb, make sure to check the wattage compatibility with your fixture and consider any dimming capabilities you may need.


Fluorescent bulbs are another type of light bulb that you might come across. They have a different shape compared to other bulbs and are often used in commercial spaces like offices or schools.

You might see fluorescent bulbs labeled as T5, T8, or T12. These numbers refer to the diameter of the bulb in eighths of an inch, with T5 being the smallest and T12 being the largest.

Fluorescent bulbs are known for their energy efficiency and long lifespan, making them a popular choice for those looking to save on electricity bills.


LED (Light Emitting Diode) bulbs are a popular choice for their energy efficiency and long lifespan. They come in various sizes, including PAR16, PAR20, PAR30, PAR36, and PAR38. LED PAR bulbs provide bright and dimmable light while using less energy compared to traditional bulbs.

They are a great option for DIY enthusiasts looking to save on electricity bills without compromising on lighting quality. When choosing an LED bulb, be sure to check the size that matches your fixture’s requirements to ensure proper fit and function.

Using the Light Bulb Size Chart

To determine the size of your light bulb, simply refer to the comprehensive chart for easy reference.

How to determine the size of your light bulb

To determine the size of your light bulb, follow these steps:

  1. Look for the bulb code: Light bulb sizes are classified using a bulb code. This code consists of a series of letters and numbers that indicate the specifications of the bulb.
  2. Measure the diameter: Use a ruler or measuring tape to measure the diameter of the bulb at its widest point. This measurement will help you identify the correct size.
  3. Check the base type: Examine the base of the bulb and determine its type. Common base types include E26, E27, GU10, and G9.
  4. Consult the light bulb size chart: Use a comprehensive guide or reference chart that lists different shapes and sizes of light bulbs to find one that matches your measurements and base type.
  5. Consider your specific needs: Determine if you require dimmable bulbs or bulbs with specific features, such as weather resistance for outdoor lighting.

Reference guide for different shapes and sizes

The article includes a reference guide for different light bulb shapes and sizes. It helps you understand the various types of bulbs, such as A19, MR16, PAR16, PAR20, PAR30, PAR36, and PAR38. The guide also covers linear fluorescent bulbs like T5, T8, and T12. There is a visual chart with illustrations to make it easier for you to identify each shape. This guide will be useful when you’re trying to find the right bulb size for your lamp or fixture.


In conclusion, “The Ultimate PAR Light Bulb Size Chart: Your Comprehensive Guide for Easy Reference” is a valuable resource for anyone looking to understand and choose the right light bulb size.

With its detailed illustrations and easy-to-follow guide, it provides a comprehensive reference for different bulb shapes, sizes, and base types. Whether you’re replacing bulbs in your home or selecting lighting options for a commercial space, this guide will help you make informed decisions.

Say goodbye to guesswork and hello to perfectly sized light bulbs with this ultimate size chart at your fingertips.


1. What is The Ultimate PAR Light Bulb Size Chart?

The Ultimate PAR Light Bulb Size Chart is a complete guide that helps you understand different light bulb sizes, their types, and dimensions for easy reference.

2. What information can I find in the light bulb chart?

In the light bulb chart, you’ll find details about various light bulb codes, from A to MR bulb shape along with their bases,diameters and specific use like outdoor lighting bulbs or ceiling fan lights.

3. Are there LED PAR bulb sizes in this guide?

Yes! The ultimate chart includes the LED Par light bulbs sizes as well as other special types such as dimmable ones for your needs.

4. Can I learn to identify linear fluorescent and dimmable light bulbs using this size guide?

Absolutely! You will know more about all shapes including Linear Fluorescent by referring through these charts that list down every type’s specifications.

5. Why does outdoor lighting need specific sort of bulbs?

Outdoor lighting requires certain sorts of bulbs because they have different diameters and base types suitable for open spaces which are covered comprehensively in our guides.

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