Different Types of PC Case Fan Sizes to Know

PC case fans play an integral role in keeping the system and its components cool. PC case fans are phenomenal ad crucial parts of your PC cabinet and making the right choice will eliminate the risk, noise, and other disturbing factors at bay. But, how should you determine which one is the right for your Personal Computer?

There are many different sizes of PC cases available and many get confused about which one should they buy for their PC case. Well, it seems a bit confusing at first, but if you know the right size and its usage you will automatically get your answer, that too without taking any risks!

Types of PC Case Fan Sizes

There are numerous sizes of PC cases and we will try to jot down almost all of them for you in this guide.

40mm Fan

The top on the list is a 40mm fan of 1.57 inches. This one is one of the smallest fans that ever existed to cool down your system. It can spin around 8000 RPM (Rotation per Minute) or even more.

40mm fan
Image: Noctua

As it is the smallest fan it is usually used for small devices like Mini PCs, SFF, and HTPC.

This one is usually around 1.57 inches and in most cases, these fans are not being used anymore because they were loud and required more energy to function. We can say they are now obsolete.

80mm Fan

80mm fans were quite popular for a very long time. They were known and used to cool down heatsinks of CPUs, and some specific graphic cards as well.

80mm case fans
Image: Noctua

80mm fan, which is around 3.1 inches, has an average RPM of 6000-7000. This type of fan is typically found in mini PCs, small form factor PCs or compact-sized desktops.

Although these fans are used in small devices, however, they are quite loud because of the RPM. They work fine and have a good lifespan as well, but if you really hate loud noise coming out of your PC, then stay away from an 80mm fan.

Almost all small devices are comprised of 40mm and 80mm fans. These fans work fine for these devices and another important factor is your PC built and its support for different fan sizes. So, small fans are kind of compulsory for small devices.

92mm Fan

Big cases need bigger cooling fans and we all know that necessity is the mother of invention. To cater for the cooling needs of bigger desktops, a 92mm fan is the right option.

92mm Fan
Image: Zalman

It is measured at 3.6 inches. The idea was to have a fan that rotates at lower RPM and works even better than ever before.

92mm was an invention for even better case fans, but this one got lost in the track of time.

This 3.6 inches case fan was no better than 80mm. It was slightly moderate and the difference between RPM was also not something to brag about.

A 92mm case fan created a boom at first but now it has become obsolete. Very few devices support 92mm and this one is not being used in any kind of PC case anymore.

120mm Fan

120mm case fans are the most popular ones you’ll find on desktop PCs. We can also say that a 120mm fan is the universal PC case fan around the globe.

120mm case fans
Image: Cooler Master

120mm supports almost all kinds of devices, be it Mini ITX, Mid-tower or high-end Full-tower PC case, a 120mm easily mounts on any type of PC case.

Another great fact about 120mm is that it works at lower RPM, usually around 2000 to 3000 RPM, while pushing more air inside your PC case. In short, it is a fan with less noise, is more efficient and a good fit for almost all devices.

140mm Fan

140mm is the upgraded version of 120mm fans, but more powerful. Unlike 120mm, they are a good fit for the mid-tower and full-tower PCs only. You cannot mount a 140mm case fan on smaller desktop PCs.

140mm case fan
Image: be quiet

If we talk about high-end computers and mid-towers, you will see a lot of them equipped with 140mm case fans. It provides even better airflow than any other PC case fan till now and it works even well if you use a liquid cooling radiator.

The price of a 140mm case fan might be a bit high than the average 120mm, but they are worth the investment. Keep in mind that bigger case fans make a lot of noise. So always opt for 140mm case fans from a reputable brand.

180mm Fan

The next on the list is the 180mm or 7 Inches PC case fan. The 180mm fan is relatively larger than 140mm and is relatively found in PC cases that promote high airflow.

180mm fan
Image: Silverstone

This fan is not built for small or mid-sized PCs. Instead, it is used only in high-end full towers because it gives a very efficient cooling and airflow at very low RPM.

So, if you work on high-end systems that require a huge fan for better cooling, 180mm is the go-to option, otherwise, 120mm or 140mm would do the same kind of job at a lower price.

200mm Fan

Finally, we have the 200mm high-end case fan for full-tower or EATX PC cases. The 200mm case fans cannot fit on a smaller case.

200mm case fan
Image: Thermaltake

On average, a 200mm fan gives you 800 RPM, which is far more silent than 80mm or 40mm fans. The larger the size of the PC case fan, the more cooling it would do.

There are even bigger and more powerful PC case fan sizes available in the market, for example, 220mm case fans, but they are built for bigger PC cases and their usage is also very specific.


The PC case fans differ in size due to compatibility and usage needs. The smaller PC cases need smaller fans and the large PC cases need bigger fans. Large-sized fans mean great airflow and low RPM which also means less noise. The most common and efficient PC case fan is 120mm however, you first need to check if it is compatible with your PC and what is your need in the longer run.

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