A Guide to Choosing the Best Air Filter for Your Home's Needs

The right filter for your home depends on three things: the size of your filter slot, the right MERV rating for your needs, and the right depth for your system. Get those three correct and you're done.

Step 1: Size

Pull out your existing filter and look at the side of the frame. The size is printed there, usually in a format like 16x25x1 (width × height × depth). Write it down. If you can't find a printed size, measure the slot itself: length, width, and depth.

Step 2: MERV rating

MERV (Minimum Efficiency Reporting Value) measures how effectively a filter captures particles. For most homes, the choice is between MERV 10 and MERV 13:

• MERV 10 — captures everyday dust, pollen, and pet dander. Best for healthy adults and most homes.
• MERV 13 — captures finer particles including smoke, bacteria, and some viruses. Best for allergy sufferers, homes near busy roads or wildfires, and anyone who wants the highest level of residential filtration.

Step 3: Depth

Most homes use 1-inch filters. Some systems are designed for 2-inch, 4-inch, or 5-inch filters — the larger the depth, the longer the filter lasts and the more particles it can trap before clogging. Check your system manual or measure the slot to confirm.

Step 4: Replacement cadence

1-inch filters: every 60 to 90 days. 4-inch and 5-inch filters: every 6 to 12 months. Pets, allergies, or heavy HVAC use shortens those windows.

If you're stuck or your size isn't on our site, send us a message — we carry over 60 standard sizes and can usually source unusual sizes within a couple of days.