Shop by size image

Factory Direct Filters has all the popular and hard to find AC and furnace filter sizes. If you need a custom size, we can do that, too! All at factory-direct prices!

Shop AC and Furnace Filter Sizes

The quickest way to find the right air filter for your home is to shop by size, and your first step is to know which size you need. You should be able to find the size on your current filter, but if you can't, we have a Helpful Tips page that shows you how to measure your furnace or AC filter size. When shopping for your HVAC filter by size, keep in mind that the size category is based on the depth of the filter. So, for example, a 1" filter measures one inch deep.