What is the most common size furnace filter?

Currently, the most common size furnace filters are 10x20.

Where is the air filter on an AC unit?

Depending on your AC unit, the air filter slot may be located in a hard to find location. First, try checking the blower compartment or return air duct where the air is cleaned before going through the unit. The unit itself may have the air filter inserted in a specific location.

Are air filters important?

Yes, they are very important to any air system they are in. Air systems have no way of knowing whether the air they are bringing in is clean or dirty. Air filters are essential to making sure that any air brought in is cleaned before entering the system. Without filtration, the air coming in from outside may contain any number of dust, debris pollutants, and allergens.

What are the symptoms of a bad air filter?

When an air filter is bad, that can mean that it is either dirty or broken. When dirty, the symptoms include the air inside of a home drying out or stagnating and dust particles filling the air. If the air filter is broken or not working, the symptoms include any number of particles such as pollen, dust, mold, dust mites, bacteria, pet dander, smoke, and viruses.

How much is an air filter for House?

The price of a single Filter King brand air filter varies depending on its measurements. However, the price falls when you buy multiple filters per order. Orders of two or more filters are also shipped for free.

How many air filters does a house have?

This is entirely dependant on your home and the kind of AC system it has. Consult the owner’s guide for your home air system to understand how many air filters your home has and in what sizes.

Air Filter Sizes Chart

What Air Filter Size Do I Need?

Regardless of the air filter or furnace filter size you need, we have them in stock and ready to ship. Use the following size selector by selecting your filter's dimensions: width (long side), depth(short side) and thickness. You can also scroll down and use the Air Filter Sizes chart to pick the right size and quickly checkout.

Available Air Filter Sizes and Types

Can't find your size? Click here for Custom Air Filters

What Are the Most Common Air Filter Sizes

Currently, the most common size furnace filters are:

All Air Filter Sizes are Proudly Made in the USA

Filter King is a US-based manufacturer, and all our materials are produced and put together in our Alabama warehouse right here in the USA.

30-Day Money-Back Guarantee

Because we're confident of our high-quality premium filters, we offer a 30-day money-back guarantee on any furnace filter size. If for any reason you're unhappy with your purchase, reach back to us within 30 days and we'll gladly refund you. Oh, we offer free shipping too when you order 2 or more filter packs.

Subscribe and Save: Buy More, Pay Less

Why get in the trouble of buying replacement filters every month when you can get us to do it for you? Our simple and scheduled ac and furnace filter delivery service may be what you need.

Swap your ac/furnace filter on time, every time! We have a wide variety of sizes to meet your every needs.

Questions about air filter sizes?

There are hundreds of variant sizes of furnace filters because air filters and furnace are both the same. The only difference between the two is location. Filter King offers hundreds of different filter sizes capable of use for several home systems, including your furnace.

An air filter’s size is described using three different measurements. The length, width, and depth of a filter are printed out in small numbers along the frame of the filter on the cardboard edge of a Filter King brand filter. But other filters may not have this information conveniently located, and you may need to find the measurements yourself. When doing so, check to see whether the filter is square or not. If it is not square, then the smallest-size side’s measurement goes first, followed by the next side, and then finally the depth measurement. 10x15x1 is a proper example of the correct size. From the actual sizes, round up the measurements to the nearest whole numbers when you order new air filters. This rounded measurement is referred to as the nominal size and is used to match the right filter to its fitting air filter slot. By using the nominal size, you can order a new air filter that slides in and out of place with ease.