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120mm vs 140mm Case Fans [Full Comparison]

In our 120mm vs 140mm case fans guide, we are going to compare both of them to help you choose the right one for your case.

Your computer tends to generate heat every time it is tasked to do something. In order to maximize the lifespan of your PC and get the best performance out of it, investing in an appropriate cooling solution is highly recommended. When choosing a cooling solution for your PC, the first dilemma you generally face is, what fan size should you go with? Today, we will be doing a battle between 120mm vs 140mm case fans. 

Whether you are using them in a heatsink or lining them up in an AIO liquid cooler, an appropriate fan size can make a day and night difference in your PC’s thermal management capabilities. The two most common fan sizes available in the market are 120mm and 140mm fans. If you are also facing the same dilemma and need help deciding between these two fan sizes, then keep reading.

Also, read GAMDIAS AELOUS M2-1204R White Fans Review.

Key Takeaways

  • 120mm is much common fan size that can fit in most cases.
  • 120mm fans tend to be much cheaper compared to most 140mm fans.
  • 140mm fans tend to perform better than 120mm fans on average.
  • 140mm fans are also much quieter. However, they can only fit in certain casings.

Dimensions Of A 120mm Fan

120mm fans are much more common than any other fans in the market. They are generally designed to fit in most casings. Even if your case has more room and it supports bigger fans, it will still fit 120mm fans just fine. These fans tend to cater to an average PC user who does not need to run their PC on overclocked frequencies all the time while maintaining a stable temperature. Let us look at the dimensions of a standard 120mm fan in detail and see if it’s the right fit for your rig.

Dimensions of 120mm fan
Dimensions of 120mm fan

120mm fans generally have a length and width of 120mm, with a thickness of 25mm. RGB fans tend to be a little thicker than the standard, non-RGB ones. This compact design allows them to fit into most cases pretty easily. This is because it is the default choice for most users as it is readily available and costs less than bigger 140mm fans. Even the smaller HTPC or mini ITX cases have support for mounting at least two 120mm fans.

Dimensions Of A 140mm Fan

140mm fans take things a bit further. These are the fans that you will find in an enthusiast’s PC. Compared to the 120mm fans, the 140mm fans exhibit significant improvement. They are not as compatible as standard 120mm fans, but they are definitely the next best thing. Many cases have started adapting to the 140mm fans since they are becoming more popular every day. Generally. 140mm fans are around 15% bigger than 120mm. Let us look at the dimensions of a standard 140mm fan and see how much of an improvement they are over the previously discussed 120mm fans.

Dimensions of 140mm fan
Dimensions of 140mm fan

Standard 140mm fans usually have a length and width of 140mm, with a thickness of 25mm. However, a minor difference of 0.5mm should be considered since every company has its own implementation of its fans. RGB fans will also tend to be slightly thicker in order to accommodate those lights. 140mm fans are recommended if you have a micro ATX or full ATX case, as these cases have support for mounting two to three 140mm fans.

120mm Vs 140mm Case Fans Comparison

Let us compare the two most readily available fan sizes in a number of general categories and see which is better in each. Also, make sure to read our guide on how to clean PC fans as that will help you greatly. 

Cooling Performance

Let’s be honest; the primary reason why you are looking for fans in the first place is to provide a decent cooling solution to your PC. In terms of pure cooling performance, 140mm fans will always come up ahead if there are no external factors. This is simply because they occupy a considerable amount of space, which allows them to dissipate heat more efficiently. They also have bigger fan blades that can push and pull more air, enabling them to maintain a superior airflow in your casing as compared to 120mm fans.

140mm fans also tend to have a higher CFM rating. CFM, or Cubic Feet Per Minute, is the unit of measurement for a PC case fan’s airflow. So, a higher CFM rating means better airflow inside the case. Most 140mm fans tend to dominate CFM ratings compared to 120mm fans, which is solely because of their greater surface area and longer blades. Long story short, 140mm fans will almost always perform better than 120mm in terms of cooling if other constraints are kept constant. 140mm fans take the win in this 120mm vs 140mm case fans segment. 


When it comes to compatibility, no other fan size comes even close to 120mm fans. These fans dominate this category as they have become the most popular fan size globally. It is easy to recommend a 120mm fan because almost every casing in the world will support it. PC case manufacturers are forced to include support for 120mm fans in their casings because people just won’t stop buying them.

You can even carry over your existing set of 120mm fans to another case if you decide to upgrade your casing cause, chances are, even your future casing will have support for it. Whether it’s an HTPC case, a mini ITX, a micro ATX, or a full-sized ATX case, A 120mm fan will be compatible with all of them.

140mm fans have started rising in this category as they are getting popular for their cooling performance and quieter noise levels. But they have a long way to go compared to 120mm fans. Many bigger-sized ATX and Micro ATX casings support 140mm fans since it’s usually gamers and enthusiasts that demand the cooling 140mm fans provide. For an average user, 120mm fans will do just fine.

Noise Levels

Noise level is important to consider if you game on your PC without a dedicated pair of headsets. In this regard, 140mm comes the head of 120mm as it has been observed to stay quieter. This is because 140mm fans can run on a lower rpm than 120mm fans while maintaining better thermals. They do not have to move as fast in order to maintain optimal airflow. Their superior fan blades can suck more air while running at lower speeds.

The difference is not of day and night, though, as fan manufacturers such as Be Quiet! Cooler Master and Noctua are getting competitive in this market space. Some of their high-end fans are designed to stay nearly silent even while operating under peak workloads. For Example, Be Quiet! Silent Wings Pro 4 does a good job of staying silent for long hours. 

Fan Speed

Fan Speed is an important factor to consider when selecting fans for your rig. It is usually measured in RPMs or rotations per minute. As the name suggests, it is a measure of how many rotations your fan can complete in a span of 60 seconds or one minute. The fan that spins the fastest does not always mean that it will perform the best as well.

However, you should be looking for fans that spin between at least 800 rpm to 1200 rpm. 800 rpm is a good starting point if your workload does not put your components to their limits and you are more of a casual gamer who does not engage in overclocking for long periods of time. Anything above that, and you will have to get a faster fan.

120mm fans tend to be much faster than 140mm fans as they run at 1200 rpm compared to 1000 rpm on 140mm. However, the larger surface area and fan blades give 140mm fans an edge in cooling performance, as it does not need to spin as fast as a 120mm fan to dissipate heat and maintain optimal airflow.


Let’s discuss the most important thing about our 120mm vs 140mm case fans battle; the price. If you are on a budget, then 120mm is easily the better option for you. It is the better value for the money because it can do most of what a 140mm fan does while costing less. A 140mm fan will always cost more compared to a 120mm fan. But you do not always have to make that choice. You can always go for the better bang for the buck, which is 120mm. The only tradeoffs will be slightly higher temperatures and more noise.

Also Read: AIO vs Air Cooler

However, if you are not on a budget and you are someone who likes to constantly test the limit of their PC, then investing in the bigger 140mm fans is absolutely worth it. This will not only increase the performance of your PC, but it will also add years to the lifespan of your components.

120mm Vs 140mm Case: Which One To Choose? 

Now that we have compared the two different fan sizes side-by-side, let us look over some of their pros, as it will help you narrow down your choices.

Pros Of 120mm Fans

One of the biggest and obvious benefits of going with a 120mm fan is its insane compatibility. No matter what case you have, chances are, it has support for 120mm fans. They have become so popular and an easy recommendation that every case manufacturer has to consider this fan size when designing new casings.

If you purchase a set of 120mm fans and decide to upgrade your casing in the near future, chances are you won’t even have to buy a new set of fans. Your previously purchased 120mm fans will fit just fine in the newer casing, so this is another thing to consider while buying new fans.

120mm Fan GAMDIAS AELOUS M2-1204R. Image Credits: Tech4Gamers
120mm Fan GAMDIAS AELOUS M2-1204R. Image Credits: Tech4Gamers

Another reason why one might go for 120mm fans is that they are a better bang for the buck. They cost significantly cheaper than the bigger 140mm fans, and anyone who is on a budget is advised to look for 120mm fans. You will often come across PC users with support for bigger 140mm fans in their casing, but they will have 120mm fans installed in them. This is because 120mm fans are more cost-effective, and consumers prefer to save that amount and invest it in another component like a GPU or CPU.

Pros Of 140mm Fans

140mm fans tend to be 15% bigger, on average, than the standard 120mm fans. The bigger surface area allows them to dissipate more heat and ensure a better airflow inside your case. A 140mm fan will always be better in terms of cooling as compared to a 120mm fan if other constraints are kept constant. This is simply because the larger blades on the 140mm fan allow it to push more air as compared to a 120mm fan running at the same RPM.

140mm Fan DeepCool AS500 Plus <a linked

Another reason one might prefer 140mm fans over 120mm is that they run comparatively quieter. It has been observed that if you take two fans of different sizes and run them side-by-side at the same speed, the smaller fan is going to create more noise. A 140mm fan does not even have to run at the same speed as 120mm fans. It averages around 1000 rpm compared to 1200 rpm on 120mm fans while maintaining better thermals. So, 140mm is the way to go if you prefer lower fan noise.   

Factors To Look For In A Fan

Now that you know the major differences between both fan sizes and their pros and cons let us look at some of the factors you need to look for when buying fans for your rig.

3 Pin (DC) or 4 Pin (PWM)?

A DC or Direct Current fan comes with a 3-pin header. Three wires accompanying the header are for voltage, ground, and tach. Compared to that, a PWM or Pulse Width Modulation has a 4-pin header. The fourth wire is for a functionality called Pulse Width Modulation. This allows you to manually control your fan’s rpm through its software. If future-proofing is important to you, then make sure you get a fan with PWM support, as it gives you much more control over your fans than the regular ones.

4 pin PWM fan cable. Image Credits: Tech4gamers
4 pin PWM fan cable. Image Credits: Tech4gamers

Power Consumption

Before buying a fan, make sure to find out how much power it will consume. Amps (A) are used to calculate the power consumed by fans. Multiply the amps consumed by your fan by the maximum voltage it supports. This will result in the total power consumed by the fan. RGB fans are likely to consume more power since they not only have the responsibility of keeping your temperatures balanced, but they also have to make your PC look good.

Brand Quality

Investing in a renowned brand when it comes to your cooling solution is always recommended. This is because the products of these brands have not only been tested before the launch but are also reviewed thoroughly by YouTubers and Bloggers.

Make sure to look for a review of the particular fan you are going with, as it will help you see things more clearly and make a better purchase decision. Also, ensure that the fan you buy comes with an extended warranty period. Companies like Arctic, Cooler Master, and Be Quiet! are the leaders of this marketplace, and most of their fans come with appealing warranty periods.

Also Read: ARCTIC P12 SLIM PWM PST Fans Review.


RGB lighting is getting popular among gamers with every passing day. Many people use fans to set their gaming rig apart from others. If you are someone like that or follow a particular theme or color scheme with your build, then investing in an addressable RGB fan will make more sense.

This will allow you to sync the colors of your fans with the rest of your build, making it look sleek. With the option of lights being interchangeable, you can change the looks of your rig every now and then, making it look fresh from time to time.

RGB Lighting Fan. Image Credits: Tech4gamers
RGB Lighting Fan. Image Credits: Tech4gamers


This marks the end of our 120mm vs 140mm case fans guide.120mm and 140mm fans are some of the most readily available fans in the market right now. 120mm is a much more compact size that will fit most cases. These fans are also cheaper and have better value for the money. 140mm fans are approximately 15% larger than 120mm fans. Due to them being large, they are considerably better at cooling as well. They also manage to stay quiet as they do not have to spin at higher speeds in order to dissipate heat from your computer.

However, all these perks come at an additional cost. 140mm fans are generally more expensive than 120mm fans. They also consume more power and will not fit in some cases like HTPC or Mini ITX. You will probably have to get a bigger case in order to accommodate the 140mm fans.


Do 120mm fans provide sufficient cooling?

That depends on your workload. If you are a casual gamer who does not overclock their CPU and GPU, 120mm fans will suffice.

Which fans should I get if I want a quiet workspace?

140mm fans are a better choice if you want a quiet workspace since those fans do not spin that fast and still manage to keep your PC cool.

Do RGB fans consume more power?

Yes, RGB fans consume more power compared to regular fans. This is because they have a motor to run the fans and lights on the fan blades, which require more power to run.

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