Actual size: 19.875 x 24.75 x 4.25 inches
Deep pleated air filters for whole-house and commercial HVAC systems
MERV 11 filters remove up to 95% of common particles including fine dust, smoke, and smog particles. These filters reduce allergy symptoms and protect against outdoor air pollution.
Processed quickly, ships fast, free for all orders
Premium quality products crafted right here at home
Return your items within 30 days and get a full refund
Find your perfect fit with our complete size range
MERV 11 air filters are designed for homes with allergies and in some cases, asthma. Those with respiratory illnesses or compromised immune systems may benefit from MERV 11 air filters due to these filters being significantly more powerful than alternative MERV filters at capturing smaller particles, such as MERV 8.
Scroll right to see more
Check the label on your current filter or use a tape measure to get the exact length, width, and depth before selecting your size.
Nominal size
Nominal size is what you normally see printed on the label. This is usually a rounded size which is often not the true size of your filter.
Actual size
Actual size is the true size of the air filter, usually written in smaller font below the nominal size.
Measure your current air filter or the length, width, and depth of the opening slot to get the actual size. Round it up to the nearest whole inch to get the nominal size.
Installing 20x25x5 air filters couldn't be easier. Just make sure to align the arrow printed on the side with the airflow direction!
Remove the air filter from the package
Locate the arrow and point it in the direction of the fan
Slide the filter in to the slot of the central unit
For return grills, insert the filter into the grill, pointing the arrow inwards
Keeping your air filter replacement schedule in mind can be challenging to say the least. Make your life easier with Filter King's auto delivery.
No, a 20x25x4 air filter is not designed for media cabinets or housing designed for a 5-inch filter. The 4-inch filter will be much thinner, which may not fit snugly in its housing, reducing efficiency and potential airflow.
No, systems designed for 20x25x5 filters can handle MERV 13 airflow levels. The thicker, deeper design distributes particles and air across a larger surface area. This provides maximum particle capturing while minimizing the risk of an air pressure drop.
Yes. A 5-inch furnace air filter requires a proper media cabinet or whole-housing air cleaning system. These housing cabinets are typically installed between the return duct and furnace. For example, a 1-inch grille will not accommodate a 5-inch filter. Determining which air filter is right for your housing unit and home environment is key.
No, vacuuming your air filter will not help capture more pollen, dander, and dust. It can damage the filter fibers and remove the electrostatic charge from the filter itself, which prevents further accumulation of particles.
No. Installing a 20x25x5 air filter is as simple as any other filter, so long as you're working with the correct size. Simply open the media cabinet door, slide out an existing filter (while noting which way the printed frame is facing), and insert the new one. When inserting a new filter, ensure the airflow arrow is pointing toward the furnace itself.
Yes, by capturing more particles over a longer period than thin filters, your 20x25x5 air filter will significantly improve your home's IAQ, or Indoor Air Quality. Deeper pleats and a higher MERV rating ensure consistent, whole-home filtration while reducing respiratory irritants at the same time.
MERV 8 filters