DIY Supplies & Accessories
Skip to content
B&Q
Ideas & Advice
Services
My Account
Basket

Light bulb buying guide

In this guide, we take you through everything you need to know to find the right type, colour and style of light bulb for every room in your home.

Jump to:

Light bulb fitting types

The cap fitting on a light bulb is the part that connects to the light fixture, keeping the bulb in place and providing power. Knowing which cap fitting you need will make finding your new light bulbs a lot easier.

Light bulb shapes

When you're replacing your light bulbs, you also need to think about which bulb shape you need.

Some bulbs will need a like for like replacement, such as a spotlight shaped bulb. You should also consider the style of your light fixture and whether a different bulb shape will suit it.

Here are some of the most common light bulb shapes:

Replacing old bulbs

If you’re replacing an old-style energy saving CFL spiral or stick shaped bulb, you can change these to a newer LED bulb. Incandescent bulbs have now largely been removed from the market.

Light bulb brightness

The brightness of light bulbs is measured in lumens. Lumens is a measure of the light output of a light bulb. The higher the lumens, the brighter the light.

How many lumens you want from your bulb depends on the purpose of the light and whether you mainly need it for ambient, general, accent, or task lighting such as reading or cooking.

Wattage, once the standard for measuring light bulb brightness, is now primarily used to indicate energy consumption in LED bulbs. Check out the table below to learn how lumens, the new measure of brightness, compares to the wattage of older incandescent bulbs.

 

Lumens Equivalent wattage
2600lm 150w
1600lm 100w
1100lm 75w
800lm 60w
450lm 40w

It can be tricky to work out how bright a light bulb will be based on the lumens number. Below, we have some examples of common light outputs for different light fixtures.

Pendant light fitting with black cable and black surround around traditional style bulb with no frame.Pendant light fitting with black cable and black surround around traditional style bulb with no frame.Pendant light fitting with black cable and black surround around traditional style bulb with no frame.Pendant light fitting with black cable and black surround around traditional style bulb with no frame.

Hanging pendant

470-1521 lumens

Matt black downlight light fixture with three bulbs, glass light shades and traditional style bulbs.Matt black downlight light fixture with three bulbs, glass light shades and traditional style bulbs.Matt black downlight light fixture with three bulbs, glass light shades and traditional style bulbs.Matt black downlight light fixture with three bulbs, glass light shades and traditional style bulbs.

Spotlight/downlight

140-600 lumens per head

Floor lamp with black floor plate, wood vertical support and black lamp shade. Lamp is placed on wood flooring in front of white wall.Floor lamp with black floor plate, wood vertical support and black lamp shade. Lamp is placed on wood flooring in front of white wall.Floor lamp with black floor plate, wood vertical support and black lamp shade. Lamp is placed on wood flooring in front of white wall.Floor lamp with black floor plate, wood vertical support and black lamp shade. Lamp is placed on wood flooring in front of white wall.

Floor lamp

100-806 lumens

White table lamp with ceramic base with an embossed design and white shade.White table lamp with ceramic base with an embossed design and white shade.White table lamp with ceramic base with an embossed design and white shade.White table lamp with ceramic base with an embossed design and white shade.

Table lamp

100-806 lumens

Light bulb colour temperatures

When selecting your new bulbs, be sure to take the colour temperature into account. Different colour temperatures can help you to create different moods or perform different tasks.

Kelvins

Kelvins are a measure of how cool or warm a light is, and the Kelvin scale measures the colour temperature of the light. The higher the number of Kelvins (shown as K), the whiter the light will be.

Lower kelvins

Low Kelvins generate warmer, cosier lights. Low kelvin lighting is perfect for your living room, dining room, bedroom and hallway.

Higher kelvins

High Kelvins give a more energising neutral white light. This can help to create an energising, bright environment. Higher kelvin lighting is perfect for kitchens, bathrooms, and areas where you work.

Illustration on the left shows a bulb with a beam with a narrow angle, text reads 'low beam angle'. On the right, illustration of bulb with a beam angle that spreads wider. Text reads wide beam angle.Illustration on the left shows a bulb with a beam with a narrow angle, text reads 'low beam angle'. On the right, illustration of bulb with a beam angle that spreads wider. Text reads wide beam angle.Illustration on the left shows a bulb with a beam with a narrow angle, text reads 'low beam angle'. On the right, illustration of bulb with a beam angle that spreads wider. Text reads wide beam angle.Illustration on the left shows a bulb with a beam with a narrow angle, text reads 'low beam angle'. On the right, illustration of bulb with a beam angle that spreads wider. Text reads wide beam angle.

Light bulb beam angles

Selecting the correct beam angle is an important factor when buying a bulb.

A low beam angle gives directional light that highlights an area or object. Low beam angle lights work better in smaller rooms when fitted closer together.

A wide beam angle will give non-directional light. Bright lights with wider beam angles work better in larger rooms.

The material of the bulb can also have an impact on its beam angle. Plastic bulbs, for example, can have a lower beam angle compared to glass bulbs.

Illustration of a dimmer switch. Circular switch is being turned by hand. Arrow points from 0% to 100% to indicate light brightness.Illustration of a dimmer switch. Circular switch is being turned by hand. Arrow points from 0% to 100% to indicate light brightness.Illustration of a dimmer switch. Circular switch is being turned by hand. Arrow points from 0% to 100% to indicate light brightness.Illustration of a dimmer switch. Circular switch is being turned by hand. Arrow points from 0% to 100% to indicate light brightness.

Dimmable LED bulbs

Not all LED bulbs are designed to be dimmed. If you want to use a dimmer switch, make sure you choose an LED bulb that can be dimmed.

In many cases, you can use your existing dimmer switch, just remove your current bulb and replace it with a dimmable LED bulb. If your replacement LED bulb flickers or you can hear a buzzing noise, you will probably need to change your dimmer switch to one that is designed to work with low wattage dimmable LED bulbs. This is because the older style dimmer switches cannot ‘read’ the low loading of an LED bulb.

Light bulb styles

Our decorative bulbs will enhance your decor with a range of styles and shapes, from gorgeous diamonds to stunning globes. Using a combination of LED technology and vintage design, they can be easily fitted to replace ordinary bulbs with the same cap fitting.

A traditional style wall hung light fitting with a traditional style filament bulb.A traditional style wall hung light fitting with a traditional style filament bulb.A traditional style wall hung light fitting with a traditional style filament bulb.A traditional style wall hung light fitting with a traditional style filament bulb.

LED filament bulbs

LED filament bulbs look good off and on. LED bulbs are often opaque or misted in colour, which can also be described as ‘pearl’ or ‘opal’. These can make the bulb look quite plain, but now there are new models available that are completely transparent.

LED filament bulbs are designed to look more like a traditional light bulb, complete with its distinctive yellow LED filaments for that extra character that reminds us of the original Edison filament; beautifully stylish but without the high running costs and short-life span of their predecessors.

These bulbs give off a warm inviting golden soft glow when used in table or wall lamps, perfect for creating a cosy atmosphere in sitting rooms or bedrooms.

A traditional light bulb mounted on a traditional style pendant light fixture.A traditional light bulb mounted on a traditional style pendant light fixture.A traditional light bulb mounted on a traditional style pendant light fixture.A traditional light bulb mounted on a traditional style pendant light fixture.

Clear glass or amber glass?

When it comes to choosing an LED filament bulb, you also have the option of clear glass or amber coloured glass. They both show off the detail of their LED filaments with the amber glass option giving a much warmer colour temperature and the look of a retro vintage bulb.

Both are available in a wide range of shapes, and come in dimmable or non-dimmable options. Amber bulbs create a warm white light, whilst clear bulbs can be neutral as well as warm.