How To Select The Best 4000K LED Bulbs

If you’re thinking about buying a 4000K LED bulb, it would be best for you to know everything there is to know about it. You may not be aware, but not all 4000K bulbs are the same.

These bulbs can vary in many ways, starting from shapes, sizes, and even brightness. So it is extremely important for you to figure out exactly which 4000K LED light bulb fits you and your needs the best.

In this article, we’re going to explore what the term ‘4000K’ means, and what color and wattage these bulbs generally are. On top of that, we’ll also discuss the different forms of these bulbs and what purpose these lights are best for. 


4000K LED Bulb Meaning

The 4000K rating basically comes from the Kelvin color temperature scale. It’s a universally accepted color temperature scale used mostly to describe household and other utility lighting products.

The Kelvin scale ranges from 1000K to 10000K. The lower end of the scale comprises white lights with the warmest temperatures, meaning the temperatures with orange and yellow undertones. 

This rating comes from the temperature and color of a traditional incandescent light bulb. When the filament of an incandescent bulb burns at 1000 Kelvin, it emits a strong orange-yellow light. As the temperature of the filament increases, the warmth of the color gradually decreases.

Even though modern LED light bulbs do not have filaments, the Kelvin scale is still used to measure the warmth of the bulbs.

What Color Is 4000K?

As the rating on the Kelvin scale increases, the temperature of the light gets cooler, where the lights have less and less yellow undertones and more blue undertones. At the higher end of the spectrum, the lights are mostly cold tempered with a high amount of blue hue.

As 4000K is almost in the middle of the scale, it’s not a fully neutral shade of white but it is mostly white with slight yellowish undertones. 

Therefore, you can expect your 4000K LED bulb to have a light yellow tint. We should mention that the difference between ratings that are close to each other can be less than noticeable. For example, the differences between a 3000K and 4000K light bulb can be so little that you may not even be able to differentiate them just by looking at them.

What Wattage Is 4000K?

A common misconception consumers have is that the Kelvin rating on a bulb is related to its wattage. This is completely false.

The wattage of a light bulb indicates the amount of energy it requires to light up that bulb. There is no relationship between the color temperature of a bulb and its wattage.

In terms of brightness, however, there is a direct relationship between the wattage and the brightness of a bulb. This means that the more wattage a bulb has, the brighter it will be.

4000K LED bulbs with different wattages with different wattages will have different levels of brightness, but the color temperature will remain the same.

One thing we must mention is that different color temperatures may appear to have different brightness, but this is simply not true.  A 60-watt 4000K light may appear to be brighter than a 3000K one, but their brightness is the same in reality. 

The wattages for LED bulbs range from 4 Watts to 38 Watts. These bulbs produce the same brightness as incandescent bulbs ranging from 40 to 100 Watts.

Choosing the Right Shape and Size of LED Light Bulb

As you probably already know, light bulbs can come in various shapes and sizes. A 4000K LED light bulb is no different to this. Depending on exactly what you need the light for, a certain shape and size may be best suited for you.

Light Bulb Shapes Image


In the current market, you can find almost 20 different shapes of light bulbs. However, only a few of these shapes are very commonly used. 

Some of these shapes have been designed based on the most efficient usage and distribution of light. On the other hand, some are designed based on looks and aesthetics.

The most common shape is the circular shape that is commonly seen in incandescent light bulbs. These bulbs are mostly used for general purposes such as lighting indoors. 

Some shapes of bulbs are used to either focus the light on one direction or scatter the light in a manner where it doesn’t shine too brightly on our eyes. Bulbs such as reflectors provide directional light which helps increase focus.


Depending on the type of light bulb, the size indicators can vary. For a standard light bulb, these are the common sizes: 

A15 bulb: 1-7/8″ diameter
A19 bulb: 2-3/8″ diameter
A21 bulb: 2-5/8″ diameter
A25 bulb: 3-1/8″ diameter

Another important notation type you need to look out for is the base types. The base type number is made up of two things, the kind of base and the diameter.

An E-type base is a screw in base and is most common. The most commonly used base is E26, meaning that it’s a screw base whose diameter is 26 millimeters. As European bases are narrower, they mostly use E14 bases.

Things to Know Before Choosing the Perfect 4000K LED Bulb

Here are the things you need to find out before choosing your option:

  • Determine the correct base size of your bulb. 
  • Determine what bulb shape and size works for you. If you’re trying to light a general area like your bedroom or bathroom, a traditional light will do the job. For a more particular purpose like directional lighting, a reflector or another kind of bulb may be best for you.
  • Understand the ideal brightness. You don’t want to use a light that is too dim or too bright. Calculate the size of the area you’re illuminating and research the correct brightness for that area.
  • Consider issues regarding overheating. If you’re placing the bulb in an enclosed fixture or space make sure that it does not have overheating issues.
  • If you’re purchasing a 4000K LED bulb for external use, make sure to buy a product that is rated and tested for that purpose. Take a look at the product description.

How Bright Is a 4000K Light

As said earlier, Kelvin’s rating is not related to brightness. The brightness of a 4000K and 5000K light bulb of the same wattage will likely be the same.

The brightness of a light is measured using lumens. In simple terms, lumen is a measure of how much light is visible to our eyes. The higher the lumens, the brighter the light appears to our eyes. 

The good thing about light bulbs is that the wattage of a light bulb also indicates relative brightness. This means that the higher the wattage of a 4000K LED bulb, the brighter it is. 

Lumens Incandescent Watts LED Watts
 375 25 4
 450 40 6
 800 60 12
1100  75 15
1600  100 20
 2600 150 30
 3000 200 38

As we can see, using an LED light bulb gives you the same brightness as an traditional bulb while consuming a lot less electricity.

Is 4000K Good for Reading 

A 4000K LED bulb can be good for reading, but at the end of the day it really depends on what kind of reading you’re doing. 

If you’re reading for work purposes or studying, you’re better of with a white light of neutral to cooler temperatures. Cool white bulbs with temperatures around 5000K could be best for this option .However if you’re doing some leisurely bedside reading, you may be better off with a warmer white light between 2700K and 3000K. Make sure that the light enough, as reading in low brightness can be dangerous for your eyes.

All in all, a 4000K light would be a good compromise between the above two options, so consider using this temperature for both purposes.

Table Bulb

Philips 4000k LED Bulb

As you may already know, Philips is one of the leading manufacturers of lighting technologies across the globe. So it comes as no surprise that Philips has one of the largest and most dependable collection of lighting productsssss in the 4000K range.

Whether you want a traditional bulb to light up your general indoor area or a spotlight for decorative purposes, Philips has options for you.

Not to mention Philips also manufactures dimmable and smart LED bulbs, which allow you to control the brightness and switch of your bulbs remotely from your smart device.

Philips bulbs are also compatible with home assistants such as Alexa and Google Home.

Tunable White LED Light Bulb (From 2700K-6500K)

Turntable white lights are becoming one of the most sought-after lighting products these days. The biggest selling point of these bulbs are their versatility. These are easily the most multi-purpose lights out there.

Not only can you dim the lights to almost complete darkness, most importantly you can change the color temperature of the lights!

Yes you heard that right. These bulbs can produce any color temperature from 2500K warm white all the way to 6500K cool white. 

That means you can just buy one pack of Turntable white LED bulbs and light different areas of your house with different color temperatures.

These are also smart lights, allowing you to control them remotely from wherever you want.

Our Recommendation to Choose The Best 4000K LED Bulb 

Now that we’ve covered everything there is to know about 4000K LED Bulbs, you need to determine exactly which 4000K light works for you the best. 

Make sure you follow the checklist we provided on everything you need to know. Do thorough research, read the product description and reviews. 

Consider purchasing the products we have recommended above, as these are tried and tested by tens of thousands of customers who have been satisfied with their purchase.

Related Article: Do LED Lights Get Hot? (Myth or Not)