All the common air filter sizes

When you're shopping for an air filter, it's easy to get overwhelmed by the huge range of filter sizes, features, and prices available. It seems like every company makes its own kind of filter, with different features and characteristics that make it unique. But how do you know which size will work best in your home? This guide will walk you through the basics of air filters and help you choose the correct size for your air conditioning system or furnace so that you can start breathing clean air as soon as possible!

Let’s look at some common air filters


When you walk into a typical housewares store, you can find different sizes. These sizes correspond to the common sizes that circulate air in your HVAC system.


What kind of air filter size should I use?


You don’t have to offer an airtight seal if you find a proper size for your filter. However, the air filter should be installed snugly in the air filter compartment with a slight bit of space around the edges. It means a proper air filter if you can slide the air filter in one place, you can find the proper size through these ways.


Make sure the size of your air filter

It is not so hard to find the proper size, there are two ways for you to find the proper size for yourself.



1. The air filters you're currently using.


How about your present air filter? Whether it suitable for you? It's a good way to find the right size by checking your existing air filter.


● Turn off your AC system

● Remove the existing air filter from the compartment

● Find the dimensions printed on the filter frame.


The dimensions include height, width, and depth. However, in some cases, the dimensions of the air filter don't match the exact physical dimensions. Sometimes the manufacturers give the model number. You can calculate the dimensions if you have the model number. The model number is shown instead of the dimensions if your HVAC system uses a whole-house filter located near the central furnace or AC unit.


2. Check it by yourself


Measure it by yourself when the dimensions are too faded to read, and there is no air filter to look at, you need to use the DIY method.


● Measure the sides of the existing air filters like the depth

● Catch the measure for 3’long

● Measure the size and depths of the air filter compartment when there is no air filter


You need to find the proper air filter dimensions shown on your HVAC manual when it can’t work normally.


Compare actual filter size with a nominal filter size


Nominal size vs. actual size: what does it mean?

In the filter industry, there are two sizes for a filter - nominal size and actual size. When you buy a filter, it's important to know the difference between nominal and actual size.


The nominal size is the printed, labeled, or rounded size of the filter. This is the side that's displayed on the air filter. This isn't the actual size of your filter. It's usually a rounded size, such as 16x20x1. A nominal size can have several different actual sizes.

The actual size is the true size of your filter. If you measure your filter, you'd get the actual size of the filter. If this page is on the air filter, it's usually below or next to the nominal size in smaller print. An example of the actual size is 15.75x19.75x0.75. If "actual size" is printed, it means that the actual size of the filter is the same as the nominal size.

When buying a filter, make sure you get the right size. The nominal size can be deceptive because often there's more than one actual size as the nominal size.


What should I do I dont have a standard-size air filter?

Most people find it that they can't find the standard furnace filter size, which is a funny truth, most of the products that TRIGHTFILTERS sold are included in the common size of the air filter.

We are ready to prepare more and more options beyond the standard air filter sizes for American residents because of many reasons. We need different air filters of different sizes. If you can't find the proper air filter at the local air filter, you can find it through

We can make any customized air filter for you, maybe they are not the perfect one, cut to fit, pre-made, and they are set up according to your actual dimensions.

Start set up your perfect air filter after looking up our customized air filter order customized air filter order page! 


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