Collection: Simply

Simply Furnace and AC Air Filters by Size, MERV and Pack

Simply pleated air filters for furnaces, air conditioners and HVAC systems, mostly in 1-inch sizes from 10x10x1 to 24x30x1, plus a 16x25x4. Most are MERV 8, with MERV 11 and MERV 13 in a few popular sizes. Packs come in 4, 6 and 12 filters.

Find Your Simply Air Filter

Check the size printed on the edge of your current filter (length x width x thickness) and match it in the table. Each row links to its product page.

Choosing a MERV Rating

MERV rates how well a filter captures particles, and higher ratings capture finer particles. Higher-MERV filters also restrict airflow more, so check that your furnace or air conditioner can handle the airflow of a higher rating before moving up from MERV 8. If you are not sure, use the same MERV rating as your current filter or check your system's manual.

Nominal Size vs. Actual Size

The big numbers printed on a filter's edge are its nominal size (for example 20x25x1). Match the nominal size shown on your current filter. If the edge is worn, measure the filter and compare it to the sizes in the table.

How Often to Replace

Replacement timing depends on your home, pets and how much your system runs. Check your system's manual, and replace sooner if the filter looks dirty. Multi-packs let you keep spares on hand.

Our Fit Guarantee and Shipping

If the size does not fit, our Fit Guarantee and 30-day returns are described in our return policy. Shipping is free on all US orders, and orders are handled in 2 to 3 business days.

Simply Air Filter Questions

Where do I find the size? It is printed on the edge of your current filter, listed as length x width x thickness.

Which pack should I pick? The table shows the pack size for each listing. Larger packs are useful if you want a year's supply on hand.

What if I ordered the wrong size? Contact us and see the return policy linked above.