How Long Do Light Bulbs Last in Days? (Exact Answer)

Light bulbs expire after a few days. But after how many days? You might have heard the lifetime of bulbs in hours. Do you know how long the bulbs can last in terms of days? 

It is quite useful to know the lifetime of bulbs because you don’t have to rush to the store if a light bulb expires unexpectedly. When you know the expiry of a bulb beforehand, you don’t have to buy spare bulbs unnecessarily. 

Therefore, we will discuss the lifetime of different light bulbs in terms of days and how to increase their lifespan.

How Long Do Light Bulbs Last in Days?

On average, Incandescent bulbs can last around 40 to 50 days, CFL bulbs can last around 300 to 400 days, and LED bulbs can last around 4 years to 6 years. The bulbs can last longer or shorter according to the frequency of its usage and the environment it is being used. Although the bulbs are mentioned to have longer lifetime by the manufacturers, practical usage can reduce its lifetime and they may expire sooner than you expect.

Popular Light Bulb Types and their Lifespan

The common light bulb types used are:

• Incandescent
• CFL
• LED

Incandescent Bulbs

This is the old-fashioned light bulb invented by Edison and uses the same old working principle till today.

It has a tungsten filament that will heat up to 4500 ⁰F and this will produce light. So, when the tungsten filament disintegrates, the bulb will not glow and you have to replace it.

The advertised lifetime of an incandescent bulb is around 750 to 2000 hours. This roughly translates to 31 – 83 days. Although the bulbs have the capacity to last the advertised lifetime, they may not last more than 40 to 50 days due to the following reasons:

• Poor manufacturing quality
• A sudden rush of excess voltage
• Frequent turning on and off

So, the real lifespan of any incandescent bulb may lie around 50 days. This bulb type is not recommended due to its high-power consumption and lower lifetime. 

CFL bulbs

These bulbs consume very less energy and last 100 times more than an incandescent bulb. You can find a CFL bulb to last around a year comfortably. 

CFL bulbs use a mixture of mercury and argon gas inside a tube and these gases light up when an electric current is passed through. Also, the fluorescent phosphor coating helps in the luminescence.

The advertised lifetime of CFL bulbs ranges from 10000 to 20000 hours. Most CFL bulbs tend to keep up to the advertised lifetime. But there can be some instances where the bulb can fail before the advertised lifetime. The reasons are:

• The ballast present at the bulb base may fail
• Frequent switching on and off will affect the bulb’s longevity
• The plastic coating of the bulb may melt and let the gases out

Due to these reasons, the average life of CFL bulbs ranges anywhere from 300 to 400 days with practical usage. But this bulb type is way better than incandescent in terms of longevity and energy consumption.

LED Bulbs

LEDs are the most energy-efficient bulbs and it has the longest lifespan. They last 1000 times more than incandescent bulbs and 100 times more than CFLs. 

LEDs use diodes which are semiconductor materials that emit light when excited with an electric current. LED bulbs use a circuit to handle the current flow to the diode. 

Although LEDs claim 10 years of lifespan in their advertisements, practically they last around 4 or 5 years only. Poor quality LEDs last far less than the 5-year span. This drastic change in lifespan occurs due to the following reasons:

• The circuit fails before the LEDs
• Placing the LED bulbs in a high-temperature environment

The diode in the bulbs has the potential to last more than 50,000 hours. But, the circuit will fail before the diode. The primary reason for the circuit to fail is due to excessive heat. It can also fail due to a sudden increase in current flow.

If you place the LED in a high-temperature environment, it can also affect the longevity of the bulbs in a significant way. 

LEDs tend to become dimmer as time passes and this is a sign that indicates the necessity to change the bulb. 

So, there are significant differences in the lifespans of the light bulbs when compared to advertised and practical usage. 

But you can increase the lifetime of the light bulb significantly with the help of the following tips. 

Tips to Increase Lifespan of Bulbs

The following tips are common for all three types of bulbs and you can find a considerable increase in lifespan.

• Use dimmer switches instead of normal on/off switches. Because, with dimmer switches, you can reduce frequent on and off which affects the life of the bulb. Also, with a dimmer switch, you can dim the brightness by reducing the current flow which may increase the lifespan.
• Avoid high-temperature environments. Bulbs that use circuits can be affected by the heat and fail before their expected lifetime.
• Don’t mix bulb types. People are used to mixing bulb types in a single lighting fixture. For example, if you are using an incandescent bulb with an LED adjacently, the heat emitted by the incandescent will affect the LED circuit causing failure soon. 

If you follow these tips, you can easily prevent early failure of the light bulbs and reach the advertised life expectancy of the bulbs. 

Conclusion

We have now understood the lifespan of the light bulbs that are commonly used. You may not get the exact lifespan as advertised.

But you can get closer to the expected lifespan with some simple tips. Also, choosing the right type of light bulb will help you to save more energy as well as avoid frequent changing of the bulbs.