Which bulb for a bedside lamp: the foolproof guide

First find the base marked on the socket or on the bulb already in place: E27 on the vast majority of bedside lamps, E14 on slim bases. Then set the light: 2700 to 3000 K, 5 to 8 W in LED for reading, and a brightness you can turn down before sleeping.

Which bulb wattage should you choose for a bedside lamp?

The socket sets the limit, not your wishes. Look for the maximum wattage engraved on the base or under the shade: often 40 W for incandescent, which means 5 or 6 W in LED. This ceiling is set before choosing the light fittings when you take on a bedroom renovation.

This value is not decorative. A bulb more powerful than what is written heats the socket, softens the wire sheath and marks the shade at the point of contact.

Which LED bulb wattage for a bedside lamp?

Allow 4 to 5 W for accent lighting and 6 to 8 W for reading in bed. At equal wattage, bulb types are not equivalent: diffusion, colour rendering and durability vary greatly from one model to another.

• 4 to 5 W: night light, late evening atmosphere
• 6 to 8 W: reading in bed, without squinting
• Above 8 W: check on the socket, rarely useful at less than a metre

Is 40 W a lot?

For a bedside lamp, no: it is yesterday's standard. 40 W incandescent heats a lot for a moderate output, and the bulb buying guide covers these equivalences technology by technology.

If your lamp only accepts a specific model and you are still unsure, describe your socket and shade to us: simply send us your setup.

How do you know whether it is E27 or E14?

Unscrew the bulb and look at the socket: the diameter speaks for itself. An E27 measures 27 mm, an E14 14 mm. With no bulb in place, the label under the base or the model's spec sheet gives the base. Wide thread, E27; fine thread, E14.

The large base dominates by far. In a survey of 151 bedside lamp references in our catalogue as of 28 September 2026, the listings that state their base break down as follows: 56 % E27, 14 % integrated LED, 11 % E14 and 8 % G9.

• E27: wide screw thread, the bedside lamp standard
• E14: fine screw thread, on narrow bases
• G9: two pins to push in, on small glass volumes
• Integrated LED: sealed module, no bulb to replace

Small bulb for a bedside lamp: E14 or G9?

E14 means a fine screw thread, G9 two pins to push into the socket. The second is found on compact fittings and older models. The difference is explained in our article on bulb base size, diameter by diameter.

An E14 to E27 adapter, a good idea?

Rarely. The adapter lengthens the socket by a few millimetres and shifts the bulb inside the shade: the result becomes uneven and the bulb may touch the fabric.

Better to choose an E14 LED bulb in the right format, in the colour temperature that suits you. E27 base bulbs remain the reference to keep at home for a classic lamp.

And if it is the lamp you are replacing rather than the bulb, every listing in our bedside lamp collection states its base, material and assembly.

Which light should you choose for your bedside lamp, warm or cool?

Warm. Between 2700 and 3000 K, the light leans towards amber, does not dazzle and lets the eye rest. At 4000 K and above, white wakes you up: useful on a desk, tiring above a bed, especially for long reading.

The same logic applies to the other light points in the room, ceiling light included, and is covered in our article on which bulb for a bedroom.

2700 K or 3000 K, how do you decide?

A dark shade absorbs part of the light and cools the result; a white shade reflects it as it is. Our article on white or yellow light details this effect across several materials.

And if my lamp has a dimmer?

Compatibility then comes before temperature. A bulb not designed for dimming flickers, buzzes or switches off suddenly at the bottom of the range. In our survey of 151 references as of 28 September 2026, 100 listings state this point: 44 % are not dimmer compatible, 23 % are.

How dimming works is explained in our article on the dimmable or variable bulb.

Can you replace a 40 watt bulb with an LED?

Yes, it is even the only replacement that makes sense today. An LED of 5 to 6 W gives the light of a 40 W incandescent while consuming far less and heating very little. Two points to check: the base, and dimmer compatibility if the lamp has one.

Which LED for a touch bedside lamp?

An LED stated as dimmer compatible, and nothing else. Touch lamps work in dimming steps; a standard bulb flickers or refuses to light at the first step. Our selection of dimmable bulbs contains only references designed for this control.

An LED more powerful than the original bulb, is that possible?

Possible, rarely useful. The socket keeps its ceiling and the dimmer its lower limit. An LED that is too strong dazzles at fifty centimetres from the face and tires the eye late in the evening. Stay in the 4 to 8 W range.

The rest depends on the lamp itself: shape of the shade, material, height of the stem. Our article on bedside lamps looks at what really matters when buying.

How many lumens for a bedside lamp?

Allow 400 to 500 lumens for reading in bed and 100 to 200 lumens for ambient light. Output is read in lumens on the packaging, not in watts. Two bulbs of the same wattage can give twice as much or half as much light depending on their efficiency.

• 100 to 200 lm: night light, late evening atmosphere
• 400 to 500 lm: comfortable reading in bed
• Above 800 lm: unnecessary at less than a metre from the face

Why does wattage not tell you the brightness?

Because the watt measures energy consumed, not light produced. Since the shift to LED, the two no longer follow the same curve. The reliable marker remains the lumen, as detailed in our article on how many lumens for a bedroom.

Does a dimmable LED change the calculation?

It simplifies it. A dimmable bulb covers the whole range in a single reference: low before sleeping, strong for reading. The mechanism is explained in our article on the dimmable LED.