Guide to Buying LED Bulbs

Guide to Buying LED Bulbs

Guide to Buying LED Bulbs

Understanding LED Bulbs - What is an LED Bulb?

LED bulbs are energy-efficient electric light bulbs designed for use in both domestic and commercial light fittings - different bulb caps are available, including Edison screw, bayonet, GU10, MR16, etc. LED bulbs may contain one or several light-emitting diodes and come in many different bulb shapes (e.g., standard GLS, golf ball shape, candle shape). 



  • Eco-friendly 
  • Energy-efficient 
  • Low running costs 
  • Instant warm-up times* 
  • Long-life (15 - 25 years)


*Please note that certain LED drivers (needed to power some LED light strips and LED downlights) can have an approximate warm-up time of around 1-second.

  • Standard dimmer switches are not compatible with LED light bulbs. 


Standard dimmer switches cannot accurately control the low voltage required to dim LED bulbs. LED dimmer switches are available.  

How long do LED bulbs last?

A typical LED bulb is expected to perform for 50,000 hours. This time frame equates to around 15 - 25 years of normal home use. 

How the typical LED bulb lifespan compares to competitor bulbs:

  • 50x longer than incandescent bulbs
  • 20x - 25x longer than halogen bulbs 
  • 8x - 10x longer than CFL bulbs

Example: If you were to leave your LED bulbs running for eight hours per day, the bulb would function at the optimum output level for 17 years. When LED bulbs come to the end of their lifecycle, they begin to dim, indicating a new LED bulb is needed.

Types of LED Light Bulbs

There are several types of LED light bulbs available for use in both domestic and commercial applications. Outside of this main group, there are also dimmable and non-dimmable LED strip lights - these units may require a driver to power the strip, unless the product information states that the LED strip light is ‘plug-and-play’ and does not require a driver. 

The main types of LED light bulbs for home and business use are outlined below.

Edison Screw LED Bulbs

Edison screw LED bulbs come with a screw-in bulb cap. There are two main types of Edison screw LED light bulbs.

  • E27 LED Bulbs (ES)

These types of LED light bulbs have a screw-in bulb cap with a 27 mm diameter. Common applications include room and lamp lighting.

  • E14 LED Bulbs (SES)

E14 LED Bulbs (SES) have a screw-in bulb cap with a 14 mm diameter. Because they are smaller in diameter than E27 bulbs, E14s are often listed as Small Edison Screw, or SES. Common applications include smaller fittings such as wall lights and desk lamps.  

Bayonet LED Bulbs 

LED Bayonet bulbs have a push and twist style bulb cap. There are two main types of bayonet LED light bulbs:

  • B22 LED Bulbs (Bayonet)

These types of LED light bulbs have a push and twist style bulb cap with a 22 mm diameter. Common applications include room and lamp lighting. 

  • B15 LED Bulbs (Small Bayonet)

B15 LED Bulbs (Small Bayonet) have a push and twist style bulb cap with a 15 mm diameter. Common applications include smaller light fittings (e.g., bedside lamp).

‘G’ style LED Bulbs

G style bulb caps each have a two-pin base, with notable design differences between each style:

  • G9 LED Bulbs - G9 bulbs have two looped pins with a 9 mm gap between pins
  • G4 LED Bulbs - G4 bulbs have a straight bi-pin setup with a 4 mm gap between pins
  • GU10 LED Bulbs - GU10 bulbs have a small ‘foot’ on the end of each pin for push-and-twist installation 

While G4, G9, and GU10 are arguably some of the most common types of two-pin LED lights bulbs, other styles are also available (e.g., GY6.35 bulbs and GZ10 bulbs). Check your light fitting for clarity over which type of two-pin bulb you require.   

MR16 LED Bulbs

MR16 bulbs and GU10 bulbs are the two most common bulb types used in downlights. The main difference between the two types of bulbs is the voltage required to power the LED or LEDs within the unit - MR16s require a diver (also known as a transformer) to reduce the mains voltage to the required power supply. There are also design differences; note that GU10 and MR16 bulbs are not interchangeable.

How Do LED Bulbs Work?

You may have heard that LED Bulbs are the most energy-efficient bulbs on the market. The reason behind the low-energy properties of LED bulbs comes down to the design. Unlike competitor bulbs that create light as a by-product by first passing current through a ‘third-party’ filament or gas, LED technology uses the electricity itself. What does that mean?

Inside an LED bulb, the current passes through a semiconductor. This semiconductor is where the LED “magic” happens. The electricity jumps across a tiny gap in the semiconductor, giving off electrons. The result is efficient light created directly from the electricity without wasting power on heating metal filaments or gas envelopes.  

Are LED Bulbs Eco-friendly?

Unlike most competitor bulbs, LED light bulbs are made of non-toxic materials and can be recycled with normal household waste. 

For example, CFL bulbs contain small amounts of toxic mercury and must be disposed of appropriately. Halogen bulbs also come with potential disposal issues due to their intricate construction, effectively ruling them out of being recycled. 

The long lifespan of LED bulbs is another eco-friendly factor. With fewer replacement bulbs required (LEDs are expected to last for 15 - 25 years), the energy associated with recycling spent bulbs is a less frequent consideration.

What is the Equivalent Wattage for LED Bulbs?

If you are looking to retrofit your existing incandescent, CFL, or halogen bulbs with LED technology, you may be wondering about the equivalent wattages with competitor bulbs.

  • 20 W CFL bulb

= 12 W LED bulb equivalent 

  • 60 W Incandescent Bulb 

= 6 W LED bulb equivalent 

  • 60 W Halogen Bulb

= 12 W LED bulb equivalent 

  • 20 W Fluorescent Tube Light

= 24 W LED bulb equivalent 

  • 250 W Sodium Light Bulb

= 100 W LED equivalent

  • 100 W Metal Halide Light

= 30 W LED equivalent 

Before we continue, it is important to remember that wattage is not a measure of brightness. Wattage measures the power needed to light the bulb. Brightness is measured in lumens. That means, in theory, an inefficient bulb could be high wattage but low in lumens.

Are LED Bulbs Compatible with Dimmer Switches?

LED bulbs are not compatible with standard dimmer switches. Due to the low-wattage required to power LED bulbs, specialised dimmer switches are recommended. 

It is also worth noting that not all LED bulbs are dimmable. If dimmable functionality is important to you, check the product information either on the box or listed online to ensure you purchase dimmable LED bulbs.

Do LED Bulbs Work in Normal Home Light Fittings?

LED bulbs are compatible with all standard domestic and commercial light fittings. Simply retrofit your existing competitor bulbs with the same style of LED bulb regarding bulb cap. For example, if your existing halogen bulb has a 22 mm bayonet cap, make sure you purchase an LED bulb with a B22 cap.

If you are looking to install downlights or strip lights, you may require an LED driver. This is a device that converts mains electricity (240 V) to the power needed by your LED lights (e.g., LED strip lighting often requires either a 12 V or 24 V power supply, meaning you would have to purchase and fit the relevant transformer). 

Do LED Bulbs Work Outdoors?

LED lights can be used in outdoor situations where the product’s IP rating meets the considered safety requirements for the outdoor lighting project. IP ratings are used to describe the light bulb’s resistance to dust, moisture, and larger objects such as fingers and tools.  

For example, IP65 ratings show that a product is protected against dust and water from a nozzle. As the rating climbs to IP66 and IP67, the protection increases to include powerful water jets and complete submersion respectively. 

Always carry out the IP rating research relevant to your outdoor lighting project.

How Bright are LED Bulbs?

Light bulb brightness is measured in lumens. There are two things to consider regarding lumens when buying LED bulbs. First, we must look at the equivalent lumens to competitor bulbs. Second, you need to know how many lumens are required to light a room. We will look at each of these points in detail.

Lumen comparison chart: 


400 Lumens

700 Lumens

1100 Lumens

Incandescent bulb

40 W

60 W

100 W

Halogen bulb 

28 W

42 W

70 W

CFL bulb

9 W

12 W

20 W

LED bulb

6 W

10 W

18 W

Next, we must consider how many lumens you need to light your rooms. Around 10 - 20 lumens per sq ft will provide adequate lighting in living rooms whereas 70 - 80 lumens per sq ft may be needed for practical lighting in areas such as bathrooms and kitchens. 

Consider whether you require comfortable or task lighting and multiply the sq ft of the room you wish to light by the relevant number stated.