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Understanding Christmas Light Bulb Types and Sizes

This guide breaks down Christmas light types and sizes, to help you choose the right lights for your installation.

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Written by Emma Sheldon
Updated over a week ago

The "Conical" Bulbs: C9 & C7

C9 Bulb:

The classic “conical” Christmas light shape, loved for its nostalgic appearance.

  • Best used to decorate: Rooflines and large tree canopies.

  • Pairs with: E17 (Intermediate base) socket wire.

C7 Bulb:

The smaller sibling of the C9, offering similar style in a more compact size.

  • Best used to decorate: Windows, doors, and large trees.

  • Pairs with: E12 (Candelabra base) socket wire.

  • LED Type: SMD chip.


The Super-Bright "Globe" Lights: G30 & G20

G30 Bulb:

A round globe shape with a sparkling, magnifying lens that creates a bold and beautiful effect for any occasion.

  • Best used to decorate: Rooflines and large tree canopies. Warm White G30 bulbs also look great on a patio!

  • Pairs with: E17 socket wire.

  • LED Type: SMD chip.

G20 Bulb:

A smaller globe, ideal for more delicate or custom installations.

  • Best used to decorate: Windows, doors, marquee signs, and medium to large trees.

  • Pairs with: E12 socket wire.

  • LED Type: SMD chip.


C9 vs G30: Which Should You Choose?

Both the C9 and G30 are commercial grade, weather-resistant, dimmable, and designed for long-term durability with stable LED color and brightness.

  • Pick C9 if you want that unmistakable traditional holiday look and a bulb that evokes classic, festive décor.

  • Pick G30 if you’re looking for something discreet, modern, and suitable for multiple occasions—even when the lights are off.


String Lights: C6 & 5mm

C6 String Lights:

Mini, classic conical bulb shape.

  • Best used to decorate: Shrubs, small to medium tree canopies and railings. Wrapping trunks, pillars and columns is not recommended.

  • Install with: Co-axial light string adapter, splitters, and extension cords.

  • LED Type: Diode.

5mm String Lights:

The most versatile and popular mini-lights with a bright, sparkling effect.

  • Best used to decorate: Shrubs, small/medium trees, intricate trunk/branch wrapping, pillars and columns.

  • Install with: Co-axial adapters, splitters, and extension cords.

  • LED Type: Diode.


Patio & Festoon Bulbs: Edison, G50 & Spiral

S14 Edison-Style Bulb:

A soft vintage look, with a double filament. Available in warm white.

  • Best used to decorate: Patios, balconies, backyards, weddings, and hanging pendant lights.

  • Install with: E26 suspensor strings or pendant sockets.

  • LED Type: Series filament.

G50 Bulb:

Large globe, vintage effects for indoor/outdoor use.

  • Best used to decorate: Patios, balconies, marquees, and room accent lighting.

  • Install with: E17 socket wire.

  • LED Type: Series filament.

ST64 Spiral Bulb:

The largest option, available as 120V plug-in or 5V battery operated.

  • Best used to decorate: Patios, marquees, events, and room lighting.

  • Install with: E26 pendant socket or adapter for battery operation.

  • LED Type: Series filament.


Still unsure which bulb is right for you? Consider your project size, location, and the visual mood you want. For tough decisions, try a sample pack or reach out to us for advice.

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