Light Bulb Specs, Lighting 101

Light Bulb Average Rated Life Time Hours

light bulb average rated lifetime hours

Some bulbs last longer than others. In the light bulb industry, the lifespan of a bulb is referred to as “Average Rated Lifetime Hours” (ARL).

Average rated lifetime hours indicate how long it takes for a certain percentage of light bulbs in a test batch to fail, and are measured and labelled using hours and an “L rating”. For example, if 100,000 bulbs were tested and 70,000 bulbs (70%) failed after 1,000 hours, this bulb would have an average rated life of 1,000 hours at L70. Here are a few more examples:


2,000 hours at L50 indicates that 50% of light bulbs had failed at 2,000 hours.

5,000 hours at L70 indicates that 70% of light bulbs had failed at 5,000 hours.

12,000 hours at L80 indicates that 80% of light bulbs had failed at 12,000 hours.

20,000 hours at L95 indicates that 95% of light bulbs had failed at 20,000 hours.

Another important aspect to take into consideration is that all light bulb ratings are carried out under perfect laboratory conditions. There are numerous other factors that will determine the life of any light bulb. Electrical surges, extreme cold, vibration and extreme heat are just a few examples of instances where the Life time of the product will be affected. Any number of factors could determine the performance and ultimately the life of a light bulb.

How to determine average rated lifetime hours

Our online bulb shop makes it easy to determine the average rated lifetime hours for any bulbs. Here’s how:

  1. To find the average rated lifetime hours, scroll down below the light bulb image for the product you have selected. Here, we have selected a 6watt GLS LED BC B22 Bayonet Cap in Warm White.

Screenshot of Where to Find Average Rated Lifetime Hours Information Lightbulb Co Website Redesign

  1. Below the light bulb you will see a button labelled “Additional Information.” Click on it.

Screenshot of Where to Find Average Rated Lifetime Hours Information Lightbulb Co Website Redesign

  1. After clicking on “Additional Information” you will see detailed information about the light bulb. To find out the average lifetime hours, scroll down to “Lamp life (hours)”. The average rated lifetime hours will be listed to the right.

how to determine average rated lifetime hours

How long do light bulbs last?

Different types of bulbs have different average rated lifetime hours.

Average Rated Lifetime Hours

Typical Range

Incandescent bulbs generally have the shortest lifespans. The average incandescent bulb light span is approximately 750 -2,000 hours. However, many people still find them appealing because of their relaxing and aesthetically-appealing hue.

Fluorescents are a long-lasting option, running for anywhere from 24,000 to upwards of 36,000 hours. They are best used in places where they will be left on for consistent periods of time, such as offices or popular areas of the home like the kitchen.

CFLs might take a moment to warm up and achieve full brightness, but they can go a long time between replacements, typically lasting between 8,000 and 20,000 hours. These bulbs have come a long way since their invention, and now offer a variety of colours and shapes to choose from, including beautiful designer options like plumen and squirrel cage bulbs.

Halogen bulbs are a more efficient alternative to incandescents, and can last up to twice as long while maintaining their crisp, white light till the end.

LEDs are the longest-lasting light bulbs, working for years longer than their counterparts. The average LED bulb lifespan is about 50,000 hours.  They come in a variety of styles, shades, and shapes, making them an ideal energy-efficient and enduring option.

How to make your light bulbs last longer

Follow these two suggestions to extend the average lifespan of your light bulbs:

1. Buy the right bulb for the job

Some bulbs are specially designed to withstand the unique conditions of particular placements, such as outdoors or inside appliances. In most cases, an “incorrect” light bulb will still operate, but its lifespan and performance will decrease and a replacement will likely be required sooner than expected.

There are a few key places where you should use specially marked bulbs, such as:

  • Outdoors
  • Dimmers
  • Appliances
  • Closed fixtures

Here are a few more examples of special uses:

Incandescent and Halogen Bulbs

With filament bulbs like halogens and incandescents, it’s important to pick the right product for the task because a hot filament can be easily damaged by vibrations and may eventually snap. For example, appliance bulbs come with reinforced filaments so they can stand up to the extra strain, which keeps your oven or refrigerator brightly lit for as long as possible no matter how many times you open and shut the door.

Check out our selection of appliance bulbs:

The golden rule for filament bulbs

You should only handle filament bulbs when they are at room temperature.

Incandescent and halogen bulbs have filaments that warm up quickly, which is beneficial for lighting a room, but the heat makes the filament brittle. Because of this, moving a filament light bulb while it’s hot increases the likelihood that the filament will be damaged. The more you move an incandescent or halogen bulb while it is warm, the greater the risk that the filament will snap, resulting in a prematurely burnt-out bulb. To limit damage to your filament bulbs and increase their lifespan, make sure you only move them after they’ve have had time to cool down after being turned off.

Fluorescents and CFLs

These bulbs should only be used in places where they will be turned on for longer than 15 minutes, as they are not built or tested to be turned off and on frequently. CFLs also prefer a cool, dry environment, so they are best kept out of bathrooms.


Dimmable bulbs are the most commonly encountered special case for LEDs. If you are going to use LEDs in a dimmer, make sure they are dimmable bulbs. A non-dimmable LED bulb will function in a dimmer, but often at the detriment of its lifespan and performance – non-dimmable LED bulbs are prone to flickering and can emit a high-pitched noise when used with dimmers. Take a look at these dimmable LEDs:

2. Use bulbs effectively & efficiently

Turning your lights on takes the bulb from 0 to 100 in seconds, flooding it with electricity that can, in some cases, gradually weaken parts of the light bulb. This is part of the typical wear and tear on light bulbs, but there are ways to limit the amount of stress, thereby increasing light bulb lifespan.

Here are three tactics that might increase the lifespan of your bulbs:

  • Keep the Lights On: Fluorescent, CFLs, and HID lamps are impacted by on/off cycles more significantly than other types of bulbs. Frequently turning them on and off or regularly leaving them on for less than 5 minutes can decrease the lifespan of these bulbs. As such, it’s best to use these bulbs in places where they will be left on for longer periods of time.
  • Use Dimmers: With incandescents, flipping the switch floods the bulb with electricity and quickly increases the heat of a filament. By using a dimmer switch, you gradually warm up the bulb, helping it to last longer by limiting the risk of thinning the filament and lessening the chance of it blowing.
    Additionally, dimmers decrease the amount of voltage hitting the bulb, which reduces the amount of stress placed on the light bulb and improves its longevity. Just remember to choose a bulb that is dimmable in order to ensure performance and lifespan, especially when selecting LEDs and CFLs. Browse our selection of dimmer switches:

1 X 400w Trailing Push On And Off 2-Way Mirror Chrome Varilight Dimmer Switch

3 X 300w Trailing Push On And Off 2-Way Twin Plate White Varilight Dimmer Switch

2 X 250w Trailing Push On And Off 2-Way White Varilight Dimmer Switch

1 X 400w Trailing Push On And Off 2-Way White Varilight Dimmer Switch

  • Operate at Lower Power: Operating a light bulb at a higher voltage than what it is stated to handle on the package can significantly decrease the longevity of your light bulb. In the UK, buildings operate at approximately 230V, so buying a bulb rated for at least 230V is important for ensuring that you get the longest life and best performance from your lighting.

Find the perfect bulb

Our service team can help you find a bulb that will last.

If you have any questions about average rated lifetime hours, our expert service team can help you find the perfect bulb for your space. Call us at 01869 362222, email, or for instant expert advice use, our live chat.

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About Sarah Levison

Sarah is a lighting expert at The Lightbulb Company with a background in hospitality and a keen awareness of the important role lighting plays in our everyday lives. She has worn many hats with us over the years, developing an extensive knowledge of lighting and the lighting industry. She is passionate about working with customers, understanding their needs, and providing them with the best solutions.

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