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Custom Air Filters

Step 1 - Select the desired filter dimensions (height is smaller dimension)

(6 filters per case )
Please Note FAQ Close

Our custom filter sizes are currently available in depths of 1", 2", and 4". Please make sure that you enter the correct dimensions below as we do not allow returns on custom air filters. Sizes are available in increments of 1/8th of an inch, and are sold in cases of 6 filters.

When ordering a custom size filter, make sure that you select dimensions that will fit the opening. Custom filters are manufactured to the exact size that you specify (allowing for 1/8" tolerance of each side). We will prompt you if the size you select meets the dimensions of a standard size filter. Read more

Filters Fast custom filter sizes are currently available in depths of 1", 2", and 4". Please make sure that you enter the correct dimensions in the drop down boxes. X and Y sizes are available in increments of 1/8th of an inch, and the filters are sold in cases of 6 filters.

Terms: Nominal Size: The printed value of a filter dimension. (15"x20"x1")
Actual size: Actual or real sizes of filters are typically .5" less than the printed dimension or nominal value listed on the filter. A filter of 20"x24" would be 19.5"x23.5"

Step 1. Select your Merv rating. In this step you will tell the system which Merv rating you want to create your filter from. There are 3 different Merv ratings that we provide in our Custom Air Filters. Each Merv rating has specific features associated with it and how it will perform as a high efficiency filter. For more details click the "?" near each of the Merv options on the screen.

Step 2. Select the Depth of filter. Once you have selected your Merv rating you are ready to select the depth of the filter you are creating. Most common house filters are 1" in the depth or thickness. If you measure your filter to find the real thickness you will find that it isn't the same dimension as it states on the filter. This difference in the real dimension to the printed dimension are industry standards and can be confusing. The printed size on a filter is called nominal size and is not the real dimension of the filter. So a 1" thick filter is normally .75" thick. To make it easier to talk about sizes we use the nominal dimensions to refer to filter instead of the actual or real size. Because you are creating a filter by selecting the real dimensions, it is important to know the real dimensions of your filter instead of the nominal or printed dimensions that show on your filter. We will show you the nominal dimension for the Depth or thickness because there are only 1",2", or 4" sizes. Now you would select 1" for your filter if you are replacing a .75" filter, if your filter is 1.75" that would be a 2" filter and a 4" is 3.5"

Step 3. Select the Height and Width dimensions. Now it's time to specify the height and width of the your custom filter. Of the 2 dimensions the height is the smaller one. Measure that side and select the closest value in the drop down list that matches your filter. In the case of not finding an exact match, most times it's better to round down. A filter that is too big to fit in the opening or too small to stay in place, will be problematic. Now go ahead and select the width that best matches the longer dimension of your filter from the drop down list. We're almost done!

Step 4. Select the number of cases. This is the last step. Now select the number of cases that you want to order. We currently ship our custom filters in cases of 6 filters per case.

You will notice that there is a box to the right of the height and width drop down boxes that says "Custom Size". The system will alert you in this window, if you should end up defining a filter with dimensions that match one of our standard sized filters. This will also allow you to go ahead and order the standard filter by pressing the add to cart button just like adding a custom filter order to your cart. And of course you can return to this page and define more filters to order.

Ships in 5 to 7 business days.

Step 2 - Select the MERV filter performance

Reviews from Trustpilot

Customer Reviews:

Total Reviews: 251 Average Rating: 4.75 / 5.0

Robert Shinn2023-12-06

Need a hard to find filter. This is the place to order from.

Collected by
Terry C2023-12-06

Arrived almost overnight. Just what I needed

Collected by

Great price and they fit perfectly. Extremely fast delivery.

Collected by
Ignacio Ruelas2023-10-05

Great product, Good quality and fit perfectly on my Unit. Thank you very much!!!

Collected by

Any sizze yoou need, fast service , shipping and decent price ! Easy to order on-line !

Collected by
Mark Aldrich2023-09-24

Quality product for a fair price.

Collected by
Susan Jeffries2023-09-22

Works great and is very efficient.

Collected by

Custom ordered filter fit perfectly!

Collected by
Phil M2023-09-12

quick delivery

Collected by

I was very happy with customer service.

Collected by
Sunni Winkle2023-09-08

The filters are perfect. Exactly what I needed.

Collected by

With Filters Fast I was able to buy 3 HVAC filters for less than the price of 1 at our local filter provider!

Collected by
Wendy Howard2023-09-01

Great quality products sized exactly to your specifications.

Collected by
Nathan Gordon2023-08-31

quality product and excellent service.

Collected by

Thank you Filter Fast sending correct size and saving us money.

Collected by
Alvaro Navarro2023-08-03

Well fitted to size! Thanks

Collected by

Did not like quality of filter and when I called to complain the assurance was not delivered well

Collected by
Maury S2023-07-14

Proper fit

Collected by

The HEPA 8 filters were equal to those sold at the big box stores & I didn�t need to trim them down to fit!

Collected by
Fast delivery2023-07-05

These actually fit and did a great job filtering the smoke coming down from our neighbors to the north. Only lasted a couple of weeks, but at least we were not breathing in the particulates.

Collected by
Close Healthier Indoor Air Quality

Filters Fast MERV Air Filters effectively reduces pollen, dust, pet dander, mold spores, dust mites and other allergens from indoor air. Removing these airborne particles can help improve allergies and alleviate sinus irritation that can cause watery eyes, itchy throat, coughing, and sneezing. Filters Fast Merv 8, 11, and 13 furnace filters, AC filters are now available.

Green Technology

The Filters Fast MERV air filter meets the Green Building Council's latest LEED (Leadership in Energy and Environmental Design) Indoor Air Quality Requirements for occupant health. That makes this filter a quick and efficient way to achieve points toward your company's LEED Certification. And in case you didn't know LEED certification can earn you tax breaks, which is just one way this filter can save you money!


MERV, or Minimum Efficiency Reporting Value, indicates when a filter will be least efficient. So the higher the MERV rating, the more efficient the filter. It should be noted that most fiberglass spun filters such as those found in your local grocery store are usually only a MERV 1 or MERV 2. This can affect the efficiency and air flow of your heating and cooling system, causing it to work harder to produce the same air flow and costing you more money! The Filters Fast MERV 8, 11, and 13 Filter features a low pressure drop, which means less impact on your energy use, which again will save you money!

Quality Construction and Capacity

The Filters Fast MERV 8, 11, and 13 filter is constructed of a galvanized, corrosion resistant metal support grid and 100% electrostatically charged synthetic graded density media. The media used is resistant to a wide range of chemicals and will not absorb moisture, which can support microbial growth.

The Filters Fast MERV 8, 11, and 13 filter's pleats are designed in a way to promote maximum surface area and dust holding capacity. The pleats are actually bonded to the frame to prevent any dust bypass. This means higher efficiency and air quality. These filters have 15 pleats per lineal foot which creates a greater surface area to catch airborne particles than standard filters. That also means that in most cases you don't have to change them as frequently!

Merv Chart Close Window
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