How To Measure Pc Fan Size?


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In the world of computers, fans play a crucial role in keeping the system cool. When replacing or upgrading fans, users often need help determining the right PC size. Have you ever wondered how to measure a PC fan size accurately? The size of a PC fan is an essential factor to consider. It determines compatibility with the computer case and ensures optimal cooling performance.

Don’t worry; we’ve got you covered! Understanding the correct fan size for your computer is crucial for maintaining a well-efficient system. Whether you’re a seasoned PC enthusiast or a novice user, you can choose the perfect fan for your needs.

Measuring a PC fan’s size might seem daunting, but it’s simpler than you might think. You can determine the appropriate fan size by following a few straightforward steps. It will fit without a glitch into your computer case. In this guide, we will explore measuring the size of a PC fan.

Understanding PC Fan Sizes

Understanding PC Fan Sizes
Understanding PC Fan Sizes

Understanding the components is crucial for measuring them. Before measuring, let’s learn about the critical elements of a PC fan’s size. It will help us understand the measuring process better.

Fan Diameter

The diameter of a fan is the primary factor that determines its size. Fan diameter is typically measured in millimeters (mm). It can range from as small as 80mm to as large as 200mm or more. To calculate the diameter right, you can use a ruler or calipers.

Fan Mounting Holes

The mounting holes are another crucial aspect to consider when measuring PC fan size. The mounting holes are where the fan attaches to the computer case. These holes are positioned at specific intervals. It plays an important role in ensuring the fan fits securely. You can use a ruler or a measuring tape to measure the mounting hole spacing.

Fan Thickness

Fan thickness is an important measurement. Consider it along with the diameter and mounting hole spacing. The thickness of a fan refers to its depth or how far it extends into the computer case. It is typically measured in millimeters. To measure fan thickness, you can use a ruler or calipers. It determines the distance from the front of the fan to the back.

Measuring PC Fan Size

Measuring PC Fan Size
Measuring PC Fan Size

Now that we have a good understanding of the critical components. It involves determining the PC fan size. Let’s dive into the step-by-step process to learn how to measure Pc fan size:

Step 1: Power Off and Open the Computer Case

Before measuring, you must power off your computer and unplug it from the wall outlet. Opening the computer case will give you direct access to the fan and make the measuring process more accessible. Refer to your computer’s manual or search online for specific instructions on how to open your particular model’s case.

Step 2: Locate the Fan

Once the computer case is open, locate the fan you wish to measure. Fans are usually found at the case’s front, rear, or sides. In some cases, you may have multiple fans installed. Identify the lover you want to measure so you can focus your measurements on that specific fan.

Step 3: Measure the Diameter

Place your ruler or calipers across the center of the fan to measure the fan diameter. Ensure that the measuring tool spans the widest points of the fan. Read the measurement in millimeters and note it down. Its height will help you determine the correct size when shopping for a replacement fan.

Step 4: Measure the Mounting Hole Spacing

Next, measure the distance between the rising holes on the fan. Position your ruler or measuring tape at one hole’s center and measure straight across to the center of the adjacent spot. Record this measurement in millimeters. Mounting hole spacing ensures the fan can be tightly attached to your computer case.

Step 5: Measure the Fan Thickness

Place your ruler or calipers at the front and measure straight back to the rear to measure the fan thickness. It will give you the depth of the fan. Record the measurement in millimeters. Fan thickness is crucial as it determines how much space the fan will occupy within the case.


How do I know my fan size?

To determine your fan size, measure the fan’s diameter using a ruler or calipers.

Are PC fans one size fits all?

PC fans are not one size fits all; they come in various sizes, ranging from 80mm to 200mm or more.

How much space do PC fans need?

PC fans need adequate space within the computer case to ensure proper airflow and cooling.

How will my computer fan fit?

To know if a fan will fit, measure the available space in your computer case and compare it to the fan dimensions you are considering.

What is the best fan layout for a PC?

The best fan layout for a PC depends on factors like case design, component placement, and airflow requirements. It’s recommended to research specific case and fan configurations for optimal cooling performance.


In conclusion, knowing how to measure PC fan size is essential for ensuring compatibility and optimal cooling performance within your computer system. By measuring the diameter, mounting hole spacing, and fan thickness, you can select the right size for your needs. Remember to power off your computer and open the case. You use a ruler or calipers for precise measurements. PC fans are not one size fits all and come in a range of sizes, so it’s crucial to measure and choose accordingly. Also, ensuring that your PC case has enough space to accommodate the fan you wish to install is vital.

Understanding these measurements, consider factors like case design and airflow requirements. This knowledge helps in deciding on fan replacements or upgrades. Well-sized and positioned fans are crucial for maintaining optimal temperatures and preventing overheating. They also contribute to prolonging the lifespan of your components. So, take the time to measure your PC fan size and enjoy a well-ventilated and cooled computer system.

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