Banker's Lamp Bulb Size: A Comprehensive Guide

Gregory Jul 01, 2026

When it comes to choosing the right bulb for your Banker's Lamp, size matters. The size of the bulb not only affects the light output but also influences the overall aesthetics of the lamp. Let's delve into the world of Banker's Lamp bulbs, exploring the ideal sizes and their impacts.

Fanbulous Matte Glass Bankers Lamp Pull Chain Plug In Nickel Base one_size | 5749848661459
Fanbulous Matte Glass Bankers Lamp Pull Chain Plug In Nickel Base one_size | 5749848661459

Banker's Lamps, with their green glass shades and adjustable arms, are iconic desk lamps that have been around since the early 20th century. They're not just functional; they're also a statement piece in many offices and homes. The bulb you choose can enhance or detract from this classic design.

14 in. Vintage Gold Bedside Lamp with Orange Glass Shade, Retro Desk Light with Pull Chain Switch for Bedroom or Study
14 in. Vintage Gold Bedside Lamp with Orange Glass Shade, Retro Desk Light with Pull Chain Switch for Bedroom or Study

Understanding Bulb Sizes

Bulb sizes are typically measured in eighths of an inch, with the most common sizes ranging from A19 to A23. The number represents the bulb's diameter in eighths of an inch. For instance, an A19 bulb has a diameter of 19 eighths of an inch, or about 2.375 inches.

Better Homes & Gardens 19" Gold/White Modern Glass Banker Desk Lamp, Size:19"
Better Homes & Gardens 19" Gold/White Modern Glass Banker Desk Lamp, Size:19"

Other than size, consider the bulb's base type. Most Banker's Lamps use medium base (E26) bulbs, which are the standard size for table and floor lamps. However, some older lamps might use candelabra base (E12) bulbs, so always check your lamp's base before purchasing.

Common Bulb Sizes for Banker's Lamps

Green Glass Bankers Desk Lamp With Wireless Charger, Usb Charging Port For Ho...
Green Glass Bankers Desk Lamp With Wireless Charger, Usb Charging Port For Ho...

Here are some common bulb sizes for Banker's Lamps and their characteristics:

  • A19 (2.375 inches): This is the most common size and fits most Banker's Lamps. It provides a good balance between light output and energy efficiency.
  • A21 (2.625 inches): Slightly larger than A19, A21 bulbs can provide more light but might not fit all lamps. They're great for larger desk lamps or those with adjustable arms that can accommodate bigger bulbs.
  • A23 (2.875 inches): These are less common and typically used in floor lamps or other large fixtures. They provide plenty of light but might not fit in standard Banker's Lamps.

Bulb Type and Light Output

Art Deco Bankers Lamp, 1930s
Art Deco Bankers Lamp, 1930s

Besides size, the type of bulb also affects the light output. Here are a few options:

  • Incandescent: These traditional bulbs provide a warm, soft light but are less energy-efficient. They're great for creating a cozy atmosphere but aren't the best choice for task lighting.
  • CFL (Compact Fluorescent Light): CFLs are more energy-efficient than incandescents and last longer. However, they can take a few seconds to reach full brightness and may contain mercury, making disposal more complicated.
  • LED (Light Emitting Diode): LED bulbs are the most energy-efficient option, lasting up to 25 times longer than incandescents. They reach full brightness instantly and are available in a range of colors and temperatures.

When choosing a bulb for your Banker's Lamp, consider the size of your lamp, the amount of light you need, and the type of bulb that suits your preferences. A well-chosen bulb can enhance the functionality and aesthetics of your lamp, creating a perfect blend of form and function.

LUXO BANKERS LAMP
LUXO BANKERS LAMP

Maximizing Light Output and Efficiency

Once you've chosen the right size and type of bulb, there are a few more tips to maximize light output and energy efficiency:

Timberlake Tiffany Style LED Bankers Lamp with Stained Glass Shade Black
Timberlake Tiffany Style LED Bankers Lamp with Stained Glass Shade Black
Dynasty Classics Corp. Tablets & Accessories | Vintage 1988 Dynasty Classics Brass Banker Desk Lamp Light Adjustable | Color: Gold | Size: Os
Dynasty Classics Corp. Tablets & Accessories | Vintage 1988 Dynasty Classics Brass Banker Desk Lamp Light Adjustable | Color: Gold | Size: Os
1stdibs Table Lamp - Radionic Trans Co. Bankers Lamp American Art Deco Steel, Chrome
1stdibs Table Lamp - Radionic Trans Co. Bankers Lamp American Art Deco Steel, Chrome
Bankers Lamp Green Glass | Vintage Brass Library Light | Dark Academia Office Decor | Executive Desk Lighting
Bankers Lamp Green Glass | Vintage Brass Library Light | Dark Academia Office Decor | Executive Desk Lighting
an antique brass desk lamp with a black cord plugged in to it's base
an antique brass desk lamp with a black cord plugged in to it's base
Charlton HomeĀ® Banker's Desk Lamp & Reviews | Wayfair
Charlton HomeĀ® Banker's Desk Lamp & Reviews | Wayfair
a brass desk lamp on a white background
a brass desk lamp on a white background
Matted Glass Bankers Desk Lamp with Pull Chain Swi, Size:14.17" x 10.43", White
Matted Glass Bankers Desk Lamp with Pull Chain Swi, Size:14.17" x 10.43", White
Hastings Home Lamps 16-in Black Bankers Desk Lamp | 149317ZGW
Hastings Home Lamps 16-in Black Bankers Desk Lamp | 149317ZGW
Linnmon Bankers Lamp, Green Desk Lamp With Pull Chain Switch, Retro... Fast Ship
Linnmon Bankers Lamp, Green Desk Lamp With Pull Chain Switch, Retro... Fast Ship
Retro Desk Lamp With Brass Base| Bankers Table Lamp With Pull Chain| Antique look Library Lamp| Green Shade Traditional Lamp
Retro Desk Lamp With Brass Base| Bankers Table Lamp With Pull Chain| Antique look Library Lamp| Green Shade Traditional Lamp
Brass Office Desk Lamp | Color: Gold | Size: Os
Brass Office Desk Lamp | Color: Gold | Size: Os
Newrays Classic Bankers Desk Lamp With Pull Chain Switch, Adjustable Gooseneck Design For Task Lighting, E26 Socket Base Requires Bulb Not Included  greenGlass/Metal
Newrays Classic Bankers Desk Lamp With Pull Chain Switch, Adjustable Gooseneck Design For Task Lighting, E26 Socket Base Requires Bulb Not Included greenGlass/Metal
a lamp that is sitting on top of a table next to books and a cup
a lamp that is sitting on top of a table next to books and a cup
Bankers Table Lamp - Dia 27cm x H 37cm / Gold & Green / AU plug
Bankers Table Lamp - Dia 27cm x H 37cm / Gold & Green / AU plug
a green desk lamp sitting on top of a metal base with a gold plated arm
a green desk lamp sitting on top of a metal base with a gold plated arm
Green Glass Bankers Desk Lamp with LED Bulb,15.15inchH,Red Copper Finish Base
Green Glass Bankers Desk Lamp with LED Bulb,15.15inchH,Red Copper Finish Base

Use a Reflector Bulb: Reflector bulbs have a reflective coating on the inside of the glass, directing more light downward. This can increase the light output by up to 30% compared to a standard bulb.

Positioning Your Lamp

Proper positioning can also enhance light output:

  • Position the lamp so the light shines down onto your work surface, not into your eyes.
  • Use the adjustable arm to direct the light where you need it most.
  • If your lamp has a shade, consider removing it to allow more light to escape.

Clean Your Lamp

A clean lamp can provide up to 20% more light than a dirty one. Dust and grime can accumulate on the bulb and shade, reducing light output and efficiency. Regularly clean your lamp to maintain optimal performance.

In the end, the perfect bulb for your Banker's Lamp depends on your personal preferences and needs. Whether you prefer the warm glow of an incandescent, the energy efficiency of an LED, or the soft light of a CFL, choosing the right size and type of bulb can transform your lamp into a functional and stylish addition to your space.