Nominal Size Vs Actual Size

BestAir furnace filters are easy to install yourself. Sometimes the challenge is selecting the right size for your unit. There are many different sizes to choose from and it can be confusing. The information below should help you determine the exact size you need. There are 2 different types of measurements. There is nominal size and actual size. Here is the difference between the two.

Nominal size is the size you see printed on the side of your filter. It stems from the actual size, which is rounded up to the nearest whole inch. 

Actual size is just what it says: the actual size of your filter to a very precise degree. The actual size is accurate to one eighth of one inch. 

For Example:

Our BestAir 3000 Series: AC Furnace Air Filter For Carrier/Bryant 20 x 25 x 5 is labled as
20″ x 25″ by 5″ which is the Nominal Size. The Actual Size is 19 7/8″ x 24 5/8″ x 4 3/8″.

So keep this in mind when you are purchasing your new BestAir Furnace Filter.