Which Light Bulb Should I Buy? The Ultimate Guide to Choosing Light Bulbs

light bulb types

Choosing the right light bulb is easy when you know what you’re looking for. If you’re not sure which light bulb is right for your lamp or light fitting, use our light bulb buying guide here to guide you. To choose the right light bulb you will need to know:

  1. Which type of light bulb cap or base your light fitting needs
  2. Which shape of light bulb you need
  3. Which type of lighting technology you need (e.g. LED)
  4. What level of light bulb brightness you need
  5. Whether you need a dimmable or non-dimmable bulb

Not sure about a few of these? Not to worry; here’s an easy step-by-step guide to show you what everything means and which light bulb you should buy:

Step 1. Light Bulb Caps and Fittings

You will have already noticed that light bulbs are available with a range of different fitting types, also known as caps or bases. Choosing the right light bulb cap fitting is the first essential step to light bulb buying, as the wrong cap will not work with your light fitting.

The main types of light bulb caps are as follows:

  • Bayonet Cap
  • Small Bayonet Cap
  • Edison Screw Cap
  • Small Edison Screw Cap
  • GU10 Cap

Not sure which cap is which? Here’s a chart of the most common household bulb types, which will help you match up your old bulb with the right cap type. Each type has its own code, which is always displayed on packaging and will help you match up your old bulb with the correct new one.

which light bulb cap

Less common bulb types include MR16, MR11, G4 and G9, which are traditionally halogen bulbs. Halogen bulbs are are being phased out as of September 2018, but if you have these light fitting types you should easily be able to find retrofit LED versions to replace old ones.

Here’s a little more information about common the most common light bulb types:

which light bulb should I buy

Step 2. Light Bulb Shapes

Now you know which light bulb cap you need, you need to decide which bulb shape you want to get. Light bulbs come in all shapes and sizes, and multiple shapes can be used for each fitting type. For example, a classic-shaped light bulb and a candle-shaped bulb can both be found with standard bayonet cap fittings, so this stage is in part down to preference and also in part down to the style, shape and size of your light fitting.

Please also note, the names for light bulb shapes are not universal in the same way as the cap fittings are, so there may be some variation here. Not sure which light bulb shape you need? Here are the most common light bulb shapes you can purchase; if you still have your old bulb simply match it up to the closest shape on our chart below.

which light bulb shape

If you don’t have your old bulb for reference, you can pick which bulb you think would look best in the fitting in question. Downward-facing pendant ceiling lights usually suit traditional and globe-shaped bulbs, upward-facing chandelier fittings often look great with candle-shaped bulbs, and table lamps can use practically any bulb shape providing it fits safely within the lampshade.

Step 3. Light Bulb Technology

Do you know which type of light bulb technology you should be using for your light fitting? The four most common types of light bulb technology that most people are familiar with include:

  • Incandescent
  • Halogen
  • LED
  • Energy-Saver / CFL (Compact Fluorescent Lamp)

Incandescent bulbs and halogen bulbs have now been phased out and are no longer being manufactured, so you won’t be able to buy these any longer. LED light bulbs are your best course of action as they are the most energy efficient and last the longest. Some halogen bulbs are still available to buy, though these will not be around for long and only have an average lifespan of around 2 years.

Making the switch to LED bulbs is easier than you might think, as most types of halogen and incandescent bulb light cap fittings are available to buy as retrofit LED lights.

Step 4. Light Bulb Brightness

If this is the first time in a long while that you’re shopping for a new light bulb, you may notice that things are a little different now. Most of us have spent years getting used to shopping for light bulbs by wattage (which indicates the amount of energy the bulb uses to power itself), but technology has moved on. With the phase-out of incandescent and halogen bulbs, watts are no longer a relevant measurement of light bulb brightness.

Light bulb brightness is now measured in Lumens, which is purely a measurement for brightness rather than energy consumption. You will find that the wattage indicator on LED light bulbs looks very low, but this is purely because LED lights require less energy to produce a brighter light.

Not sure which light bulb will match the brightness of your traditional 40 or 100 watt bulbs? Use our handy Lumens to Watts conversion chart to find the right bulb to suit your light fitting and your lighting requirements. Or, if you already have an LED bulb, check the bulb to find the lumens rating.

which light bulb lumens to watts conversion

Step 5. Dimmable or Non Dimmable?

And finally, when choosing which light bulb you need you should consider whether or not you want your light fitting to be dimmable. Dimmable light bulbs are great for spaces that are used for more than one purpose, i.e. reading, working and watching TV, as you can set the lights to the exact level of brightness you need at any one time.

However, not all bulbs are compatible for using with dimmer switches, so you need to take care when choosing your new bulb. The good news is, LED light bulbs are available to buy in both dimmable and non-dimmable versions, so you will always be able to find the right bulb to suit your needs. The packaging will always state when a bulb is dimmable, so always check closely before buying.

CFL ‘energy saver’ bulbs are not dimmable, while the remaining halogen bulbs on the market can usually be used for both dimmable and non-dimmable purposes.

And that’s it! Using this guide you will be able to easily decipher which type of light bulb you need for your fitting. Ready to shop? Check out our full range of light bulbs and accessories here at Moonlight Design.

Comments are closed here.