Bulb fittings are one of those things nobody explains until you are standing in a shop holding the wrong one. Here is a plain-English guide to the fittings you will see on our product pages, what they are for and how to choose the bulb that goes in them.
E27: the standard screw
E27 is the large Edison screw, 27 mm across. It is the most common fitting for pendants, floor lamps and table lamps in the UK and Europe. If a product page says E27, almost any E27 LED bulb will fit; the shade or the fixture determines the maximum size and wattage. You will sometimes see E26 on products designed for the US market; it is the same thread and E27 bulbs fit, but check the voltage rating on the product page.
E14: the small screw
E14 is the small Edison screw, 14 mm across, used in chandeliers, smaller wall lights and bedside lamps. Candle-shaped and golf-ball bulbs are usually E14. Multi-arm chandeliers often take several E14 bulbs, so buy them in a pack and make sure they match.
GU10: the spotlight
GU10 is the twist-and-lock fitting used in spotlights, downlights and track lights. GU10 bulbs run on mains voltage, so no transformer is needed. Look at the beam angle: around 36 degrees for general lighting, narrower for highlighting a picture or a wall.
G9 and G4: the small pins
G9 is a small two-pin fitting used in compact chandeliers and wall lights where space is tight. G4 is smaller still and usually low voltage. Both are available as LED now; check the dimensions, because LED versions can be slightly larger than the halogen bulbs they replace.
Integrated LED: no bulb at all
Many modern fixtures, including most of our ring chandeliers, linear pendants and flush ceiling lights, have LEDs built in. There is no bulb to buy or change. The upside is a slimmer design, lower energy use and often a choice of colour temperature via remote. The downside is that if the LED fails outside the warranty, the light unit is replaced rather than a bulb. In practice, LEDs are rated for tens of thousands of hours.
Three things to check on any bulb
- Colour temperature. 2700K is warm and cosy; 3000K is warm white; 4000K is neutral and best kept for kitchens and offices. Match all the bulbs in one room.
- Brightness. Measured in lumens, not watts. Roughly 400–500 lumens for a bedside lamp, 800 for a reading light, and several thousand in total for a living room.
- Dimmability. Only dimmable bulbs on a compatible dimmer will dim smoothly. A non-dimmable LED on a dimmer will flicker.
If a product page does not list a fitting, it will have an integrated LED. If you are ever unsure, send us the product link and we will tell you exactly what to buy.