How to choose a lightbulb - the complete guide

The right lightbulb is the essential finishing touch to a designer pendant or lamp. And as well as looking stylish, you’ll need the right amount of light for your purpose. Luckily we’ve made choosing the best lightbulb easy for you with this complete guide…

Selecting a lightbulb sounds like it should be straightforward, but it can be rather confusing - what with fittings, wattage, lumens and energy efficiency to worry about. Not to mention shape, size and getting that stylish retro ‘filament’ look for a proper designer lightbulb. No wonder people feel like they need a little help. So with that in mind, here’s a complete guide. Below are quick tips for choosing a lightbulb for each of the main kinds of lamp: pendants, floor lamps, table lamps, wall lights and desk lights. But first, we explain the five key factors to take into account when choosing any bulb... Stylish! A large 6 watt LED filament bulb - perfect when you want to complement a designer lamp

The five main decisions when choosing any lightbulb

1. How much light do I need?

The first thing to decide is how much light you’ll need from your lightbulb. These days everybody works in lumens, which is a measure of brightness. You can see how many lumens a bulb provides on its box, or, on our website in the information on each lightbulb page:

If, like most of us, you still think in terms of watts (a completely different kind of measure, which tells you how much energy is needed to produce light), then an old-fashioned 40-watt incandescent bulb gives about 300-400 lumens and an old 60-watt bulb gives around 500-700. (For LED lights the wattage involved is much lower to produce the same amount of light. For example, a 6 watt LED bulb can provide 450 lumens. That’s why lumens is a much better measure of brightness than watts.) How many lumens you want from your bulb depends on the purpose of the lamp. For a lamp with a particular task you’ll want more lumens. For example, for a reading light you’ll probably want at least 450 lumens. Similarly, you’ll need brighter lights over kitchen worktops and in bathrooms, whereas in hallways fewer lumens will be fine. For general ambient light where your lamp is one of multiple sources, it’s best to work out how many lumens you need in total for the room. A rule of thumb is that a sitting room or bedroom needs about 10 to 20 lumens per square foot in total and a bathroom or kitchen needs 70 to 80 lumens per square foot. So if your sitting room is 100 square foot just make sure your lightbulbs from ceiling lights, wall lights and lamps all add up to between 1000 and 2000 lumens. That way you’ll have plenty of light when everything is turned on, and plenty of flexibility for creating different ambiences when you use different light sources in combination. (See our guide to layering light in the home here).

2. What type of lightbulb do I want? (hint: it’s an LED)

There are various different lightbulb technologies on the market, all with differing qualities in terms of lifespan, energy efficiency and ambience. The four main kinds of lightbulb are:
  • Incandescent (aka standard, aka Edison) - the old-fashioned filament bulb we all grew up with. Lovely and bright, and brilliant in their time... but since some 95% of their energy is converted into heat rather than light and they have a short lifespan, they’re on the way out.
  • Halogen - about 30% more efficient than incandescent bulbs and with a typical lifespan of up to 3 years - but rather bright and harsh, so best for intense task lighting rather than indoor ambience.
  • CFL (Compact Fluorescent Lightbulbs) - these are those white curly tube bulbs known for their eco-friendly credentials. Up to 75% more energy efficient than an incandescent bulb, and they last for years. But they’re pretty hopeless when it comes to creating a nice ambience, and they are, frankly, ugly.
  • LED (Light-emitting Diode) - the technology here has improved to the point where LEDs are now the bee’s knees. Not only are they the most efficient bulb (up to 80% more efficient than incandescent bulbs) and last for decades, nowadays they can give a lovely warm light and they can look just as stylish as any Edison filament bulb. They’re very affordable now too.

Large globe LED filament bulb So the short answer to the question, ‘What kind of lightbulb do a want?’ is: ‘An LED one’.

3. What kind of ambience (‘colour’) do I want?

We’re now into the realms of personal taste. You can of course buy bulbs in different colours for decorative purposes, but even normal ‘white’ light has different ‘colours’. Slightly confusingly, this colour is measured in degrees Kelvin. And even more confusingly, the lower the ‘temperature’ the warmer the light. A candle is the ‘warmest’ light with a colour temperature of about 2,000k, while sunlight is 6,000k. Here’s a chart:

Image credit - Wikipedia Commons For most lamps in sitting rooms, bedrooms, dining rooms and so on, you’ll almost certainly prefer a colour temperature of around 2700k, known as ‘warm white’. That’s bright enough to be useful but also has a soft, welcoming ambience and is more flattering to the human face! Higher temperatures (colder ‘bright white’ colours) can be useful in garages, basements etc, and some people prefer them in bathrooms or kitchens. One more thing to consider on ambience: if your lamp is dimmable, make sure you get a dimmable LED bulb too.

4. What style of light bulb do I want?

These days you can choose from a range of LED lightbulb styles, to suit the look of your lamp. Shapes include:
  • Large format 'globe' LEDs - these look fantastic with a retro filament style
  • GLS (‘General Lighting Service’) - the classic bulb shape
  • Golf ball - small round bulbs, great for certain pendant lights
  • Candle - the thin pointy ones.
But there are also lots of other stylish variations. In general, simply go for large bulbs for large lamps, and small ones for small lamps. In addition, you can choose between pearl (coloured white) LED bulbs and clear LED bulbs which show the filament. Again, it’s a matter of taste, but as a rule of thumb choose pearl bulbs for table lamps and floor lamps which take a shade, and use a clear bulb with pendants where the lightbulb is visible, so you can show off that cool retro filament.

5. Which fitting do I need (bayonet or screw)?

Finally, there’s the fitting. This is the easiest decision because it’s entirely dependant on the requirements of your lamp - just make sure you check and get the right kind!

The two main types are bayonet (‘B’ fittings - above, left) and screw (‘E’ fittings - above right). The B system used to be predominant in the UK, but the more internationally-popular E is gradually taking over. The most common fittings are B22 and E27, and both are available in all sorts of shapes and sizes.

So those are the main factors to think about. And to help you even more, here are some quickfire, ‘rule of thumb’ guides for the different kinds of lamp..

What kind of lightbulb do I need for a pendant light?

Quick answer: If the bulb is visible go for a clear LED with a filament, as they look the most stylish. In large single pendants you could go for a large round or GLS bulb (see above). For smaller pendants a golf-ball shape might be better. In sitting rooms, bedrooms, hallways and dining rooms choose a warm white bulb (about 2700k) and make sure the total light in the room from all your lights combined is around 10 to 20 lumens per square foot. You can go brighter in kitchens and bathrooms if you wish.

A clear filament golf ball LED bulb is perfect for a clear pendant light like the Tutu

What kind of lightbulb do I need for a table lamp?

Quick answer: For table lamps with a shade a pearl LED bulb is fine in a GLS or candle shape, but go for warm white colour and if you need the table lamp for reading have at least 450 lumens.

What kind of lightbulb do I need for a floor lamp?

Quick answer: If the floor lamp’s shade covers the bulb, go for a pearl LED in a GLS or candle shape with warm white colour (around 2700k). If the bulb is visible go for a clear filament LED bulb in a GLS or candle shape.

What kind of lightbulb do I need for a wall light?

Quick answer: Small lightbulbs, golf balls and candle shaped bulbs are ideal for wall lights. Go for a warm white light, and if the bulb is visible choose a clear LED light with the filament showing. If it’s not visible then a pearl LED bulb is fine. As with ceiling pendant lights, in sitting rooms, bedrooms, hallways and dining rooms make sure the total brightness in the room from all your lights adds up around 10 to 20 lumens per square foot. Kitchens and bathrooms can be brighter if it suits your taste.

A wall light like the Mundo has a visible bulb, so go for a clear filament LED bulb

What kind of lightbulb do I need for a desk light?

Quick answer: Desk lamps are task lights so you can go for a brighter LED , e.g. 500 lumens, and choose either warm white or bright white colour. Most desk lights have hooded shades hiding the bulb, so any shape is fine, as is the matter of pearl versus clear filament.

It can be a confusing business, but we hope this guide helps you choose the right lightbulb for your lamp. You can browse all of our stylish LED lightbulbs here. And of course when you order a lamp from Pooky we’re very happy to recommend a bulb - just ask!