How do you choose the right table lamp bulb?

The cap is the part of the bulb that connects to the fitting, and using the wrong one means the bulb simply won't fit. The two most common types in UK table lamps are the E27 (large Edison screw) and the B22 (bayonet cap). Smaller lamps — particularly those with slim, decorative shades — may use an E14 small screw cap instead.

To identify which cap your lamp needs, look at the socket inside the shade. A round hole with a screw thread is an Edison screw fitting; two small pins on the inside indicate a bayonet. If the lamp is new and unboxed, the rating label on the cord or base will state the cap type directly.

Many modern table lamps are designed around E27 fittings because the wider range of LED options available in that size makes it easier to control brightness and colour temperature. If your lamp uses a less common cap such as G9 or GU10, you'll find fewer decorative bulb options, but LED versions are still widely stocked in UK hardware retailers and online.

Every table lamp has a maximum wattage rating, usually printed on a small sticker inside the shade or on the base. Exceeding this limit generates excess heat, which can damage the shade, the fitting, or in serious cases create a fire risk. The Health and Safety Executive guidance on electrical safety is clear that using fittings beyond their rated capacity is a common cause of avoidable electrical incidents at home.

With LED bulbs, the figure to watch is the watt equivalent, not the actual power draw. A 6W LED may be labelled as a 40W equivalent, meaning it produces the same light output as a 40W incandescent bulb while drawing only 6W. This matters because older lamps rated at 40W or 60W are perfectly safe with modern LEDs — you're running well within the thermal limit.

As a practical guide:

• Bedside reading lamps: 40–60W equivalent (warm, focused)
• Living room accent lamps: 25–40W equivalent (ambient, soft)
• Desk or task lamps: 60–100W equivalent (bright, neutral)

If you're unsure of the rating and the label is missing, treat the lamp as a 40W maximum until you can verify it.

Colour temperature is measured in Kelvin (K) and describes how warm or cool a bulb's light appears. For table lamps used in relaxing spaces — bedrooms, sitting rooms, hallways — a warm white bulb between 2700K and 3000K produces a soft, amber-toned glow that feels comfortable in the evening and flatters most interior colour schemes.

For a home office desk lamp or a reading light where you need to concentrate, a neutral or cool white bulb at 3500K to 4000K reduces eye strain and makes text easier to read over long periods. Avoid anything above 5000K (daylight spectrum) in a table lamp — it tends to feel clinical indoors and can disrupt sleep if used in the evening.

If you want flexibility, look for bulbs labelled as dimmable and pair them with a lamp that has a compatible dimmer switch. Dimming a warm white LED from full brightness to around 30% shifts the perceived colour even warmer, mimicking the effect of candlelight. This is particularly effective in living rooms where the lamp doubles as ambient lighting during the day and mood lighting in the evening.

When the bulb is visible — through an open cage shade, a clear glass base, or a fabric shade that glows when lit — the shape becomes part of the lamp's aesthetic. Decorative filament bulbs in globe (G95), squirrel-cage, or tubular forms are designed to be seen and add warmth and character to the fitting.

For lamps with opaque or lined shades where the bulb is hidden, the shape matters less for appearance but still affects light distribution. A standard GLS (pear-shaped) bulb spreads light evenly in all directions, making it the most versatile option. A candle-shaped bulb (C35) is narrower and better suited to slim shades where a GLS might sit too close to the inner lining.

Reflector bulbs (R-type) direct light downward and are rarely appropriate for table lamps — they're designed for recessed or directional fittings. Stick to GLS, globe, or candle shapes for most domestic table lamp applications.

Switching to energy-efficient LED bulbs is also worth considering from a cost perspective. The UK government's energy grants guidance highlights how reducing household energy consumption across all fittings — including lighting — contributes to lower bills and eligibility for certain schemes.

Smart bulbs — those controlled via an app, voice assistant, or smart home hub — are compatible with the majority of standard table lamp fittings. They screw or click in exactly like a conventional bulb and require no rewiring. The key requirement is a reliable Wi-Fi connection within range of the lamp's location.

One important caveat: smart bulbs must not be installed in a lamp connected to a wall dimmer switch. The dimmer interrupts the power supply in a way that interferes with the bulb's internal electronics, causing flickering, connectivity drops, or early failure. If your lamp is on a dimmer circuit, use a non-smart dimmable LED instead and control brightness through the switch itself.

Smart bulbs offer genuine practical benefits for table lamps specifically:

• Schedule the lamp to turn on at dusk automatically
• Adjust colour temperature from warm evening light to brighter morning light without changing the bulb
• Set scenes that dim multiple lamps in a room simultaneously

For a bedside table lamp, the ability to turn the light off without getting up is a straightforward quality-of-life improvement. Most major smart bulb brands (Philips Hue, LIFX, Tapo) offer E27 options that fit standard UK table lamp fittings without adapters.