How To Measure PC Fan Size

Pc Master Guide

Pc Master Guide

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Wondering how to measure PC fan size? Fan sizing is something that can be a little confusing for those new to the hobby. With so many different brands, sizes, and shapes of fans, it can be hard to know where to start. In this article, we will provide you with the basics of fan sizing so that you can get started buying the right fan for your needs.

When buying a fan, it is important to consider both its size and shape. Fan size refers to how large or small the fan will be when in use. Fan shapes include Circular (or round), V-Shaped, U-Shaped, and Striped. Each has its own advantages and disadvantages.

How To Measure The Size Of A PC Fan

There are a few ways to measure the size of a PC fan. You can use an outside diameter measurement, an inside diameter measurement, or a blade count.

Outside Diameter: To measure the outside diameter of a PC fan, you’ll need to remove the fan from its housing and measure its width and length.

To measure the OD, first find the center of the fan’s hub or blade. With a tape measure, measure directly across from this point to the outer edge of the hub or blade. This measurement is called the fan’s outside diameter.

PC fans come in three different sizes: small, medium and large. The OD measurements listed on most fan packaging correspond to these three size categories. For example, a small fan has an OD of 3/8 inch, a medium fan has an OD of 1 inch and a large fan has an OD of 1 1/4 inches.

Inside Diameter: To measure the inside diameter of a PC fan, you’ll need to remove the fan from its housing and measure its width and depth.How To Measure PC Fan Size

The easiest way to measure the inside diameter of a PC fan is to use a piece of wire. Cut off one end of the wire and make a small loop. Tape the other end of the wire to one side of a fan blade and measure how far down the wire extends from the blade. This will give you an approximate inside diameter for that particular fan model.

If you don’t have access to a wire, another method involves using an inch ruler and measuring how wide each individual blade on your fan is.

Some people are concerned about the blade count of their PC fans. They wonder how to measure it, and whether or not they need more than one fan.

To measure the blade count, first remove all the fans from your computer and place them on a flat surface. Measure the length of each fan blade, then multiply that number by 2. That is your blade count. If you have fewer than 2 blades on a fan, you will need to replace that fan with a higher blade count model.

If you have more than 2 blades on a fan, you do not need to replace it. However, if your computer uses very high speed fans (over 1000 RPM), then you may want to replace them with higher blade count models in order to prevent damage from happening due to overspeed.


Determining The CFM Of A Fan

CFM is a measurement that measures the amount of air that is being pushed out by a fan. A higher CFM means more air being pushed out of the computer. Higher CFM’s also mean less noise.

The common fan size is in CFM (Cubic Feet per Minute). To calculate the CFM of a fan, measure the diameter of the fan and multiply it by 3.14. For example, if a fan has a diameter of 24 inches, then its CFM would be 142CFM.

Measuring Fan Noise Levels

Noise from computer fans can be a nuisance if it’s too loud. The way to measure fan noise levels is to use an electronic sound meter. There are many different types of meters, so it’s important to find one that will work with your computer.

To start measuring, find the fan in question and note its location on the chassis (or case). Then open the case and locate the fan cable leading from the motherboard to the fan. Measure how long the cable is and note that length as well. Finally, use your sound meter to measure how loud the fan is blowing (in dBA) when it’s running at full speed.

Fan noise levels are usually measured in dBA, which stands for Decibels Averaged over 1 Second. To convert this measurement to watts, multiply by 1 million. The formula for fan speed in watts is:

Speed (in RPM) = Fan Speed (dBA) * 1,000,000 Watts

For example, if a fan is measured at 30 dBA when it’s running at full speed, the fan will produce 3,000

Considering Your Thermal Needs

Think about your thermal needs when buying a PC fan.

Find out how to measure the size of your PC fan and choose the right one for your computer.

PC fans come in different sizes, so make sure to get the one that is compatible with your computer.

Choosing the right PC fan size can save you money in the long run by reducing energy costs and improving system performance.

How To Measure PC Fan Size


In conclusion, when purchasing a PC fan, it is important to know the size of the fan. This will ensure that the fan can fit in the desired space and operate efficiently. There are many online resources that can help with finding the size of a PC fan, such as the manufacturer’s website or a fan sizing chart. By following these simple steps, anyone can find and purchase the perfect PC fan for their needs.

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