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Lightbulb cap types: Which cap fitting do I need?
There are many ways you can filter our catalogue of light bulbs to find the one you need; by wattage, voltage or price, but we think a good starting place is to select the cap fitting the bulb must have.
The cap fitting is the part of the bulb that connects it to the socket of a light fixture.
In this guide we’ll go through the most common types, their physical sizes and what they’re most often used for.
We understand that the disadvantage of buying online is not physically being able to hold the bulb and compare it to your old one.To help you match your old bulb’s fitting we’ve made a handy downloadable cap size chart. Download our cap guide below and print on A4 paper for a 1:1 scale list. Once you’ve done this hold your bulb against the guide and match like for like.
10 Popular Lightbulb Cap Types
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Name: Bayonet Cap (BC) or B22d Cap Size: 22mm diameter Commonly found: in large household lights See all B22d Bulbs > |
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Name: Edison Screw (ES) or E27 Cap Size: 27mm diameter Commonly found: in large household lights See all E27 Bulbs > |
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Name: Small Bayonet Cap (SBC) or B15d Cap Size: 15mm diameter Commonly found: in small household lights See all B15d Bulbs > |
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Name: Small Edison Screw (SES) or E14 Cap Size: 14mm diameter Commonly found: in small household lights See all E14 Bulbs > |
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Name: G13 Size: 2 pins, 13mm apart Commonly found: on thick fluorescent tubes See all G13 Bulbs > |
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Name: G5 Size: 2 pins, 5mm apart Commonly found: on thin fluorescent tubes See all G5 Bulbs > |
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Name: GU10 Size: 2 pins, 10mm apart Commonly found: on spotlights See all GU10 Bulbs > |
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Name: GU5.3 Size: 2 pins, 5.3mm apart Commonly found: on spotlights See all GU5.3 Bulbs > |
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Name: Minature Edison Screw (MES) or E10 Cap Size: 10mm diameter Commonly found: in chandeliers See all E10 Bulbs > |
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Name: Giant Edison Screw (GES) or E40 Cap Size: 40mm diameter Commonly found: in halls, factories & workshops See all E40 Bulbs > |