20x25x4 Air Filters
20x25x4 is whole-home media cabinets (e.g. 4" deep) for extended service life. It is available in MERV 8, MERV 11, and MERV 13 (deep media keeps airflow resistance low even at MERV 13). A 20x25x4 pleated filter typically lasts 6 months. The 20x25x4 label is the nominal size; the actual filter measures about 19.5 x 24.5 x 3.75 inches.
About the 20x25x4 air filter
The 20x25x4 air filter is used in whole-home media cabinets (e.g. 4" deep) for extended service life. As with all air filters, the size is given as length x width x depth in inches. The 20x25x4 label is the nominal size; the actual filter measures about 19.5 x 24.5 x 3.75 inches.
If your system uses 20x25x4, you can choose the efficiency that fits your needs — from basic equipment protection up to MERV 13 for allergies, pets, and wildfire smoke. Because this is a deep-media filter, you get high efficiency with low airflow resistance and a long service life.
20x25x4 MERV options
| MERV | Captures | Best for |
|---|---|---|
| MERV 8 | Dust, lint, pollen | Basic protection |
| MERV 11 | Above + pet dander, fine dust | Pets, mild allergies |
| MERV 13 | Above + smoke, bacteria | Allergies, asthma, smoke |
When to replace a 20x25x4 filter
A 20x25x4 (4") filter typically lasts 6 months. Replace it sooner if you have pets, allergies, or during wildfire smoke season. Hold it up to light — if you can't see through the media, it's time to change it.
Frequently Asked Questions
What systems use a 20x25x4 air filter?
20x25x4 is used in whole-home media cabinets (e.g. 4" deep) for extended service life. Check the size printed on the side of your current filter to confirm before ordering.
What is the actual size of a 20x25x4 filter?
The 20x25x4 label is the nominal size; the actual filter measures about 19.5 x 24.5 x 3.75 inches. Always order by the nominal size (20x25x4) for standard filters.
Can I get a 20x25x4 filter in MERV 13?
Yes. 20x25x4 is available in MERV 13 pleated for maximum particle capture, as well as MERV 8 and MERV 11. Custom efficiencies and frames are also available.
How often should I replace a 20x25x4 filter?
Typically every 6 months, and more often with pets, allergies, or during smoke season.
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Need help choosing the right filter?
Talk to our Canadian air filtration team. Call 1-888-973-3635 or request a quote.