Furnace Filters
Best Gas Furnace Filters (2026): Our 4 Picks Ranked
As an Amazon Associate I earn from qualifying purchases. Specs below come from each product's Amazon listing; we do not test products in person.
For a gas furnace, the Amazon Basics 20x25x1 leads this list: it is MERV 8, comes as a 6-pack, and its electrostatically charged synthetic material captures particles as small as 3 microns. If your slot takes a smaller size, the Simply 14x20x1 is also MERV 8 in a 6-pack, while the Filtrete 16x20x1 steps up to MERV 11 with 1000 MPR.
Starting out? See the main guide: Best Furnace Air Filters
Top picks at a glance
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Best OverallAmazon Basics 20x25x1 Air Filter 6-Pack9.8 View on Amazon -
Runner-UpSimply 14x20x1 Air Filter9.8 View on Amazon -
Also GreatFiltrete 16x20x1 Air Filter9.5 View on Amazon -
Also GreatFrigidaire 16x20x1 Air Filter9.2 View on Amazon
Compare the specs
Ranked on pack size from each listing, plus how many buyers have rated it. A dash (—) means we could not confirm that figure from the listing.
| Pick | MERV rating | Pack size | Weight | Warranty |
|---|---|---|---|---|
| 1. Amazon Basics 20x25x1 Air Filter 6-Pack | MERV 8 | 6-pack | — | — |
| 2. Simply 14x20x1 Air Filter | MERV 8 | 6-pack | — | — |
| 3. Filtrete 16x20x1 Air Filter | MERV 11 | 2-pack | — | — |
| 4. Frigidaire 16x20x1 Air Filter | MERV 8 | 6-pack | — | 90-day |
Amazon Basics 20x25x1 Air Filter 6-Pack
It pairs MERV 8 filtration with a 6-pack, a beverage board frame, and wire mesh support for a standard 20x25x1 slot.
- MERV rating: MERV 8
- Pack size: 6-pack
Good for
- Owners of a 20x25x1 furnace slot who want spares on hand
- Buyers who want a 6-pack changed every 60 to 90 days
Skip it if
- You need a size other than 20x25x1
- You want a higher filtration level than MERV 8
It measures 20x25x1 nominal, with an actual size of 19.75 x 24.75 x 0.75 inches, and fits standard furnaces, ACs, and HVAC return grilles. Insert it with the airflow arrow pointing toward the furnace or blower, away from the return grille. With changes every 60 to 90 days, the 6-pack provides replacements for up to 12 months.
Simply 14x20x1 Air Filter
It gives MERV 8 filtration in a 6-pack for a 14x20x1 slot, with pleated construction and up to 3 months of filtration per filter.
- MERV rating: MERV 8
- Pack size: 6-pack
Good for
- Owners of a 14x20x1 slot who want a 6-pack
- Buyers who want pleated filtration that traps 90% of airborne particles
Skip it if
- You need a size other than 14x20x1
- You want a higher filtration level than MERV 8
Its nominal size is 14x20x1, with an actual size of 13.75 x 19.75 x 0.75 inches, and it fits central units and return grilles. Follow the airflow arrows when inserting it into the filter slot. Each filter lasts up to 3 months, and the filters use 100% American components, including recycled materials.
Filtrete 16x20x1 Air Filter
It steps up to MERV 11 with 1000 MPR in a 2-pack for a 16x20x1 slot, plus 3-in-1 technology.
- MERV rating: MERV 11
- Pack size: 2-pack
Good for
- Owners of a 16x20x1 slot who want MERV 11 filtration
- Buyers who want 30-, 60- or 90-day change reminders
Skip it if
- You need more than 2 filters in the pack
- You want a size other than 16x20x1
It is a 16x20x1 filter with MERV 11 and 1000 MPR, and its 3-in-1 technology pulls in and traps particles from the air passing through it. It helps capture dust, lint, and other particles from household air. Change it at least once every 90 days. The Filtrete Smart App for iOS or Android sets 30-, 60- or 90-day reminders to change the filter.
Frigidaire 16x20x1 Air Filter
It pairs MERV 8 filtration with a pleated design, dual wire backing, and a 90-day warranty in a 6-pack.
- MERV rating: MERV 8
- Pack size: 6-pack
- 90-day warranty stated
Good for
- Owners of a 16x20x1 slot who want a 6-pack
- Buyers who want pleated filtration with dual wire backing
Skip it if
- You need a size other than 16x20x1
- You want a higher filtration level than MERV 8
It is a 16x20x1 MERV 8 pleated filter with dual wire backing, and it captures dust and lint. Installation is simple, and the filter is replaced every 3 months for best performance. The warranty is a limited 90-day manufacturer warranty.
How to choose
Match the size to your slot
Measure your current filter frame or slot before ordering, because nominal sizes differ from actual sizes. The Amazon Basics nominal 20x25x1 measures 19.75 x 24.75 x 0.75 inches, the Simply nominal 14x20x1 measures 13.75 x 19.75 x 0.75 inches, and the Filtrete nominal 16x20x1 measures 15.68 x 19.68 x 0.81 inches. Check the frame first so the filter sits snugly in the slot.
Compare MERV and MPR together
MERV is a scale for particle capture, and MPR is a separate scale used by Filtrete. Three picks here are MERV 8: the Amazon Basics, the Simply, and the Frigidaire. The Filtrete is MERV 11 with 1000 MPR. A higher MERV figure means finer particle capture in general terms, so match the figure to the particle capture you want.
Plan the change schedule
Change intervals differ across this list, so plan replacements around the pack size you buy. The Amazon Basics 6-pack provides replacements for up to 12 months with changes every 60 to 90 days. The Simply filter lasts up to 3 months, the Frigidaire is replaced every 3 months, and the Filtrete is changed at least once every 90 days. The Filtrete Smart App sets 30-, 60- or 90-day reminders, which helps keep the schedule on track.
FAQ
What size furnace filter do I need?
Measure your current filter or slot and match the nominal size. This list covers 20x25x1, 14x20x1, and 16x20x1, with actual sizes given for the Amazon Basics, Simply, and Filtrete picks.
What is the difference between MERV 8 and MERV 11?
MERV is a scale for particle capture, and MERV 11 is a higher figure than MERV 8 in this list. The Filtrete is MERV 11 with 1000 MPR, while the Amazon Basics, Simply, and Frigidaire are MERV 8.
When should I change a gas furnace filter?
It depends on the pick: the Amazon Basics changes every 60 to 90 days, the Simply lasts up to 3 months, the Frigidaire is replaced every 3 months, and the Filtrete is changed at least once every 90 days.
Do any of these filters have change reminders?
The Filtrete Smart App for iOS or Android sets 30-, 60- or 90-day reminders to change the filter.
