Can I put a brighter bulb in my light fitting?

The label saying "max 60W" was written when lamps were filaments and roughly 90 per cent of the input became heat. That heat had to go somewhere, and the fitting's plastics, the lamp holder and the cable tails inside were designed around a specific amount of it. LED changed the relationship between brightness and heat entirely, which is why the label is now both still important and much less limiting.

Safety

Step by step

1. Find the marking on the fitting.Usually inside the shade, on the lamp holder, or on a label near the ceiling plate. It states a maximum wattage and often a lamp type. If there is no marking at all, treat 60W as a conservative ceiling for filament-type lamps.
2. Understand what the limit protects.The lamp holder's temperature rating, the insulation on the tails inside the fitting, the shade material, and in a recessed fitting the ceiling void around it. All of them are heat limits.
3. Switch to lumens for brightness.Lumens measure light output. Roughly, 400 lumens replaces a 40W filament lamp, 700 lumens a 60W, 1050 lumens a 75W and 1500 lumens a 100W. An LED delivering 1500 lumens draws perhaps 14W, so a 60W-rated fitting can now carry the light output of a 100W lamp comfortably within its thermal limit.
4. Respect the limit in actual watts, not equivalent watts.This is the only trap. A lamp box saying "100W equivalent" is telling you about brightness, not consumption. Its actual consumption might be 13W, which is well inside a 60W fitting. Read the real wattage figure, which is always printed somewhere.
5. Check the enclosure question separately.A fitting's wattage limit and its suitability for an enclosed lamp are different things. In a sealed shade, heat cannot escape even at low wattage, and a standard LED lamp will die early. Buy one marked for enclosed luminaires.
6. Consider colour temperature, not just brightness.More lumens in a cold colour temperature will feel harsh rather than better. 2700K is warm and suits living rooms and bedrooms, 3000K is a neutral warm white, and 4000K is a cool white that suits kitchens, utility rooms and workshops. Matching within a room matters more than the exact number.
7. Consider the beam and the shade.If a room feels dim, more lumens in the same opaque shade may achieve very little. Sometimes the fix is a lighter shade, a second light source, or moving from one central pendant to two or three smaller sources.
8. Check the cap type before buying.B22 bayonet, E27 large screw, E14 small screw, GU10 twist-lock mains downlight, G9 capsule and GU5.3 low-voltage pins are the common UK fittings. GU10 and GU5.3 look similar and are not interchangeable — GU5.3 needs a transformer.

Tips

• Two moderate light sources nearly always look better than one bright one. Wattage limits push you towards a better lighting solution rather than away from it.
• If the fitting has a dimmer, remember the dimmer has its own LED load limits at both ends of the range.
• In an old fitting with brittle brown flex inside, more light is the least of the issues. Have it looked at rather than relamped.

Common mistakes

• Reading "100W equivalent" as 100W of load — It is a brightness comparison. The real consumption is usually a tenth of it and is what the fitting's limit refers to.
• Fitting a halogen lamp above the marked wattage "just for now" — Halogen runs extremely hot. Over-wattage halogen in a fitting rated for less is a known fire cause, and the damage to the holder and tails is permanent even if nothing catches.
• Assuming brighter is better in a bedroom — Lumens and comfort are not the same. Warm colour temperature at moderate output, with a dimmer, produces a room people want to be in.

If it doesn't work

Questions people ask