Selecting the correct LED filament bulb for a fixture requires more than matching the base type and wattage. The bulb's physical dimensions — its maximum diameter, overall length, and the position of its maximum diameter relative to its base — determine whether it will fit inside the fixture, clear the fixture's shade or globe, and produce the light distribution the design requires. A G125 globe that is 2mm too wide for a pendant's neck opening, or an ST64 that is 10mm too long for a recessed socket, creates a specification failure that costs time and money to correct.

This guide provides a complete dimensional reference for the four primary decorative LED filament bulb shape families — A-shape, G-shape, ST-shape, and T-shape — with the physical dimensions, fixture compatibility parameters, and application guidance that specifiers need to make correct selections on the first attempt.

How to Read Bulb Dimensions

Every LED filament bulb has three primary dimensional parameters:

Maximum Diameter (MOD): The widest point of the bulb, measured in millimeters. This is the dimension encoded in the model code (G125 = 125mm maximum diameter). The maximum diameter determines whether the bulb will fit through a fixture's neck opening and whether it will clear the fixture's shade or globe.

Overall Length (MOL): The total length of the bulb from the bottom of the base to the top of the glass envelope, measured in millimeters. This determines whether the bulb will fit within the fixture's depth and whether it will protrude beyond the fixture's opening.

Light Center Length (LCL): The distance from the bottom of the base to the center of the light-emitting element (the filament), measured in millimeters. This is relevant for optical calculations and for fixtures with reflectors designed around a specific LCL.

Base Length: The length of the base/driver assembly below the glass envelope. This is relevant for enclosed fixtures where the base must fit within the socket housing.

A-Shape (Standard / Pear): The Universal Form Factor

The A-shape is the most widely produced and most fixture-compatible LED filament bulb form factor. Its pear-shaped profile — wide at the top, tapering to the base — is the shape that incandescent lamp sockets were designed around, making A-shape LED filament bulbs compatible with the broadest range of existing fixtures.

A60 (European) / A19 (North American)

Dimensions:

• Maximum diameter: 60mm
• Overall length (E27 base): 115–120mm typical
• Light center length: 65–70mm typical
• Base length (E27): 30mm typical

Fixture compatibility:

• Compatible with virtually all standard lamp sockets designed for incandescent A-shape bulbs
• Fits standard pendant fixtures, table lamps, floor lamps, and wall sconces
• Maximum diameter of 60mm fits through most standard fixture neck openings (typically 55–65mm clear opening)
• Overall length of 115–120mm fits within most standard fixture depths

Application guidance: The A60/A19 is the default specification for any application where the bulb will be partially or fully concealed within a shade or fixture. Its compact dimensions ensure compatibility with the widest range of fixtures. For applications where the bulb is fully visible (bare-socket pendants, open cage fixtures), the A60's relatively modest visual presence makes it less impactful than G-shape or ST-shape alternatives.

Wattage range available: 2W–10W (200–1000 lm equivalent)

A67 (European) / A21 (North American)

Dimensions:

• Maximum diameter: 67mm
• Overall length (E27 base): 125–132mm typical
• Light center length: 72–78mm typical

Application guidance: The A67/A21 is used where higher lumen output is required in an A-shape form factor. The larger envelope provides better heat dissipation for higher-wattage drivers. Verify fixture neck opening clearance before specifying — some fixtures designed for A60/A19 have neck openings of 62–65mm that will not accommodate the A67's 67mm diameter.

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G-Shape (Globe): The Decorative Statement

G-shape bulbs are the defining product of the decorative LED filament category. The spherical glass envelope maximizes filament visibility, creates omnidirectional light distribution, and provides the visual presence that makes decorative lighting a design element rather than merely a functional component.

G80 (European) / G25 (North American)

Dimensions:

• Maximum diameter: 80mm
• Overall length (E27 base): 115–125mm typical
• Light center length: 70–80mm typical

Fixture compatibility:

• Fits pendant fixtures with neck openings of 82mm or larger
• Compatible with standard table lamp sockets
• Overall length similar to A60; fits most standard fixture depths

Application guidance: The G80/G25 is the compact globe — large enough to have visual presence as a decorative element, small enough to fit in fixtures designed for standard A-shape bulbs. It is the appropriate choice for applications where a globe aesthetic is desired but fixture dimensions limit the use of larger formats (G95, G125).

Wattage range available: 2W–6W (200–600 lm equivalent)

G95 (European) / G30 (North American)

Dimensions:

• Maximum diameter: 95mm
• Overall length (E27 base): 130–140mm typical
• Light center length: 80–90mm typical

Fixture compatibility:

• Requires pendant fixture neck opening of 97mm or larger
• Not compatible with most standard table lamp sockets (designed for A60/A19)
• Suitable for open pendant fixtures, cage pendants, and bare-socket installations
• Overall length of 130–140mm requires fixture depth of at least 145mm

Application guidance: The G95/G30 is the most popular decorative globe size for restaurant and hospitality applications. It is large enough to be a prominent visual element in a pendant cluster but small enough to be used in multiples without overwhelming the space. The 95mm diameter is the sweet spot between visual impact and fixture compatibility.

Wattage range available: 4W–8W (400–800 lm equivalent)

G125 (European) / G40 (North American)

Dimensions:

• Maximum diameter: 125mm
• Overall length (E27 base): 165–175mm typical
• Light center length: 105–115mm typical

Fixture compatibility:

• Requires pendant fixture neck opening of 127mm or larger
• Requires fixture depth of at least 180mm
• Not compatible with standard table lamp sockets
• Suitable for open pendant fixtures, large cage pendants, and bare-socket installations with adequate clearance

Application guidance: The G125/G40 is the statement globe — the largest commonly available standard globe size. It is used in high-ceiling spaces (restaurants, hotel lobbies, retail) where visual impact is the primary objective. The 125mm diameter creates a prominent visual element that reads clearly from a distance. Verify fixture clearances carefully — the G125's 165–175mm overall length and 125mm diameter require fixtures with generous proportions.

Wattage range available: 4W–10W (400–1000 lm equivalent)

G150 (European) / G48 (North American)

Dimensions:

• Maximum diameter: 150mm
• Overall length (E27 base): 195–210mm typical
• Light center length: 130–145mm typical

Application guidance: The G150/G48 is a specialty product for statement installations — hotel lobbies, luxury retail, high-ceiling restaurant spaces. Its 150mm diameter and 195–210mm overall length require custom or purpose-designed fixtures. Not suitable for standard pendant hardware; requires fixtures specifically designed for oversized globes.

Wattage range available: 6W–15W (600–1500 lm equivalent)

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ST-Shape (Straight Taper / Edison): The Industrial Icon

ST-shape bulbs — the "Edison" or "squirrel cage" form factor — have a cylindrical body with a slight taper toward the base. The visible filament (typically a multi-loop squirrel cage or spiral coil) is the defining visual element of the industrial chic aesthetic.

ST58 (European only)

Dimensions:

• Maximum diameter: 58mm
• Overall length (E27 base): 140–150mm typical
• Light center length: 85–95mm typical

Application guidance: ST58 is a European-market code with no direct North American equivalent. It is slightly narrower than ST64 and is used in applications where the smaller diameter is required for fixture clearance. Less common than ST64 in the decorative market.

ST64 (European) / ST19 (North American)

Dimensions:

• Maximum diameter: 64mm
• Overall length (E27 base): 155–165mm typical
• Light center length: 95–105mm typical

Fixture compatibility:

• Fits pendant fixtures with neck openings of 66mm or larger
• Overall length of 155–165mm requires fixture depth of at least 170mm
• Compatible with cage pendants, industrial pendants, and bare-socket installations

Application guidance: The ST64/ST19 is the canonical Edison bulb — the product most associated with the industrial chic and Edison revival aesthetics. The elongated cylindrical form factor with a visible squirrel-cage or multi-loop filament is the defining visual element of this style. The ST64 is the most widely specified decorative LED filament bulb after the A60/A19 and G95/G30.

Wattage range available: 4W–8W (400–800 lm equivalent)

ST68 (European) / ST21 (North American)

Dimensions:

• Maximum diameter: 68mm
• Overall length (E27 base): 165–175mm typical

Application guidance: ST68/ST21 is a slightly larger variant of the ST64/ST19. Used where a more substantial visual presence is desired in the Edison form factor. Verify fixture neck opening clearance — the 68mm diameter requires a minimum 70mm clear opening.

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T-Shape (Tubular): Linear Elegance

T-shape bulbs are cylindrical tubes with a consistent diameter along their length. Unlike A, G, and ST shapes, T-shape bulbs have no taper — the maximum diameter is maintained along the full length of the glass envelope. This creates a distinctive linear aesthetic that is used in bar counter lighting, pendant arrays, and applications where a horizontal light source is desired.

T30 (European) / T10 (North American)

Dimensions:

• Maximum diameter: 30mm
• Overall length (E27 base): 120–130mm typical
• Light center length: 70–80mm typical

Application guidance: The T30/T10 is the compact tubular — used in vanity strips, small pendant fixtures, and applications where a narrow tubular profile is desired. The 30mm diameter is small enough to fit in fixtures designed for standard A-shape bulbs.

T45 (European) / T14 (North American)

Dimensions:

• Maximum diameter: 45mm
• Overall length (E27 base): 150–165mm typical
• Light center length: 95–110mm typical

Application guidance: The T45/T14 is the medium tubular — the most popular T-shape for decorative applications. Used in bar counter pendants, linear pendant arrays, and applications where the tubular form factor is a design element. The 45mm diameter and 150–165mm length create a substantial visual presence while remaining compatible with most pendant hardware.

Wattage range available: 4W–8W (400–800 lm equivalent)

T95 (European) / T30 (North American)

Dimensions:

• Maximum diameter: 95mm
• Overall length (E27 base): 200–220mm typical

Application guidance: The T95/T30 is a specialty large-diameter tubular for statement installations. Its 95mm diameter and 200–220mm length require purpose-designed fixtures. Used in high-end hospitality and retail applications where a dramatic linear element is desired.

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Dimensional Quick-Reference Table

Shape	Code (EU/NA)	Max Diameter	Overall Length	Fixture Neck Min.
A-shape	A60 / A19	60mm	115–120mm	62mm
A-shape	A67 / A21	67mm	125–132mm	69mm
Globe	G80 / G25	80mm	115–125mm	82mm
Globe	G95 / G30	95mm	130–140mm	97mm
Globe	G125 / G40	125mm	165–175mm	127mm
Globe	G150 / G48	150mm	195–210mm	152mm
Edison	ST58	58mm	140–150mm	60mm
Edison	ST64 / ST19	64mm	155–165mm	66mm
Edison	ST68 / ST21	68mm	165–175mm	70mm
Tubular	T30 / T10	30mm	120–130mm	32mm
Tubular	T45 / T14	45mm	150–165mm	47mm
Tubular	T95 / T30	95mm	200–220mm	97mm

At Luminaries Factory, dimensional drawings with full tolerances are available for all products in our decorative LED filament range. Our specification team can assist with fixture compatibility assessments for any project. Contact us to request dimensional data sheets.