How to Find the Right Furnace Filter
Locate your filter, read its size, and avoid common measuring mistakes.
Read guide →A simpler way to choose an HVAC filter
Find the right HVAC air filter in under 60 seconds.
Learn the basics, use the FilterMatch Finder, understand why a filter is recommended, and shop confidently for the size and MERV rating that fits your home.
Free HVAC Filter Finder
Personalized Recommendation
Results in Under 60 Seconds
No Signup Required
FilterMatch Finder
Get a practical recommendation in three steps.
Choose your size and household needs. We will show a suggested MERV rating and explain the reasoning.
1. What size is your current filter?
Look for three numbers printed on the cardboard frame, such as 20x25x1.
2. What matters most in your home?
Select all that apply.
Your Home Air Quality Report
Your personalized filter recommendation
Excellent starting point
View Recommended FiltersYour size
Why We Recommend This
Recommended for
Replacement schedule
InstallationUsually under 2 minutes
ImportantConfirm HVAC compatibility
The reminder is stored only in this browser and appears when you return after the due date. No email or account is required.
How We Recommend Filters
A balanced recommendation for your household.
Every recommendation is tailored using the information you provide in the FilterMatch Finder.
✓Your air filter size
✓Your household needs, including pets, allergies, smoke, dust, or everyday use
✓Common residential MERV ratings
✓The balance between filtration performance and healthy airflow
Before choosing a higher MERV rating
Higher filtration can increase airflow resistance. Check your HVAC manual or ask a qualified technician before using a rating your system may not support.
Learn how MERV ratings work →Learning Center
Understand your filter before you buy.
MERV Ratings Explained
Understand filtration ratings, airflow, and which level may fit your household.
Read guide →MERV 8 vs. 11 vs. 13
Compare the three common residential ratings side by side.
Read comparison →Frequently Asked Questions
Common air-filter questions
How often should I change my filter?
Many 1-inch filters are replaced every 60–90 days. Homes with pets, heavy dust, smoke, or allergy concerns may need more frequent changes.
Where do I find my filter size?
Check the cardboard frame of the current filter. The nominal size is usually printed as width × height × depth, such as 20x25x1.
Is a higher MERV rating always better?
No. Higher ratings can capture smaller particles but may create more airflow resistance. Use a rating your HVAC system supports.
Which direction should the arrow point?
The airflow arrow should point toward the blower or air handler and away from the return-air opening.
Can I use a thicker filter?
Only when your filter cabinet is designed for that depth. The third number in a size such as 20x25x1 indicates the nominal thickness.
Does FilterMatch sell filters directly?
No. FilterMatch provides educational guidance and links to third-party retailers where you can compare available products.