Measure Case Fan

How To Measure Case Fan? – Know From The Expert 2024

A case fan is a vital part of your computer. Often, when you want to buy a new case fan for your computer, the process may bother you with accuracy problems. There are certain ways that you should follow to measure your case fan.

So, how to measure a case fan? In short, most often you will find case fans sized 120mm, 80mm, 92mm, 140mm, or 200mm but if you don’t know the size of your case fan then you can measure that with a scale and measuring tape. Unfortunately, taking this measurement isn’t as simple as any usual measurement. For measuring your case fan you have to follow a few tricks. This article will get you familiar with those tricks.

Keep on reading to know more about case fan sizes and how to measure the size of your case fan. Let’s get started!

How To Measure Case Fan?

How To Measure Case Fan

Case fans usually come in some specific sizes and those sizes are the same almost all over the world. Mostly 120mm fans are available everywhere. But if you are not sure about the size of your case fan and want to know the size of your case fan then we can help you in that case.

For measuring the case fan you will need a measuring tape. You can take a scale also. No other thing is needed for measuring your case fan. So let’s dive into the process.

  1. First, take the case fan out and lay it on a table.
  2. Now take the measuring tape and simply measure across the case fan to find out the size. But not diagonally. You have to measure the 4 sides of the case fan.

This process can be used for measuring your case fan. If you don’t have access to a fan and you need to know which sized fan case you need or you want to measure the fan by measuring the case then there is a way to help you at that phase. The steps are:

  1. You have to take the case and find the holes in each angle. There are 4 holes in 4 angles.
  2. Measure from the middle of one hole to the middle of another hole. But again not diagonally.

This way you will get to know which size fan you will need. For example, if you find a measurement that says 105mm from each hole to another hole of the case then you will need a fan that is 120mm. Also, you can know the fan size by this process as you can measure the fan by measuring the case in this process.

Why Should You Measure the Case Fan?

The case fan is one of the most important parts of your computer. Simply case fans balance the temperature of your computer by boosting the airflow through the case and bringing the surrounding case temperature closer to the external surrounding temperature. All of these things depend on the size of your case fan.

Although running at the same RPM the larger fans will push more air out than the smaller ones. The larger fans will spin much more slowly but that doesn’t mean they work less. They still push more air than the smaller ones. Instead of pushing less air by fewer spins, they push more air and also provide you with a lower noise level.

So to have the good features you should measure the case fan and pick the larger one. Another thing that should be considered is that most of the cases are made to have 120mm or 140mm fans. That’s why before buying or replacing your case fan you must know the size of the case fan. Don’t purchase any case fan before measuring the size of that case fan.

What are the Usual Computer Case Fan Sizes?

In modern PC cases, a 120mm fan is the most popular size because of its features. Also, this is available in almost every region. However, there are some other sizes of case fans that are also found in modern PC cases. Those are:

  1. 200mm
  2. 140mm (As popular as 120mm)
  3. 92mm
  4. 80mm

These are some sizes of case fans that are also found in PC cases. But 120mm and 140mm are considered to be the favorite of all because they push more air than the smaller ones by fewer spins and lower noise. Though 200mm case fans are the biggest; it isn’t much popular because it is more costly than 120mm and 140mm case fans.

On the other hand, smaller ones such as 80mm, and 92mm are not as popular as bigger case fans nowadays because they produce more noise than bigger case fans and don’t push as much air as bigger case fans.

Things to Consider While Measuring the Case Fan

Now you know that measuring computer case fans is important enough. The measurement will make many things easy. Also, you will get to know if that case fan is suitable for your computer or not. At that phase, you may think about which things should be considered when you measure your case fan.

A few things should be considered while measuring the fan. Those are:

  • While measuring the fan you should think if the case fan is compatible with your computer or not.
  • Nowadays many PC cases are not capable of holding small case fans. So you have to check if the fan case is big enough to fit in your PC case.
  • Make sure that you are not measuring the case fan not diagonally.


case fans faqs

What size case fans do I need?

The size of the case fans you need for your PC depends on the size of your PC case and the available fan mounts. Common sizes for case fans are 80mm, 120mm, 140mm, and 200mm. You can check the specifications of your PC case to see what size fan mounts are available and choose the size accordingly.

It’s also important to consider the airflow needs of your system. If you have a high-performance PC with multiple components that generate a lot of heat, you may need larger or more fans to ensure adequate cooling. You can consult a cooling calculator or talk to a computer hardware specialist to determine the appropriate size and number of case fans for your system.

Do all case fans fit?

No, not all case fans will fit every PC case. The size and number of fan mounts available in a PC case are determined by the design of the case and can vary from one model to another. It’s important to check the specifications of your PC case to determine the size and number of fan mounts available and choose case fans that are compatible.

It’s also important to check the spacing of the fan mounts to make sure the case fans you choose will fit properly

Can I connect 3 pin fan to 4 pin header?

Yes, you can connect a 3-pin fan to a 4-pin header, but you will lose some of the features and control that are available with a 4-pin fan.

A 4-pin header provides power to the fan and allows for control of the fan speed, which is not possible with a 3-pin fan connected to a 4-pin header. In this case, the fan will run at full speed, which may not be ideal for all situations.

However, if you don’t need to control the fan speed and just want to use the fan for basic cooling, you can connect a 3-pin fan to a 4-pin header. Just make sure that you connect the red wire, which is the power wire, to the 12V pin and the black wire, which is the ground wire, to the ground pin. The other wire, if present, is the tachometer wire and can be left unconnected.

What does PWM stand for?

PWM stands for “pulse width modulation.” It is a pulse signal that controls the fan speed.

Closing Words

If you have reached until now, the whole process should be obvious to you. So now you know how to measure case fans. Follow the process accurately to get the perfect measurement for you. We have also shared a few things to consider before you measure the case fans.

Although there are a few fixed-sized case fans, you need to decide on which one to choose, and that’s where this article is going to help you. A simple mismatch in the size of the case fan can bring adjustment problems to your computer and money loss as well. So get ready with your measuring tape and start the work now! All the best in your work!

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