Furnace Filters
Best 20x30 AC Filters (2026): 5 Picks Compared
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 20x30x1 slot, the Simply 20x30x1 Air Filter leads this list as Best Overall: a MERV 8 pleated filter in a 6-pack with up to 3 months of filtration. The MERV 11 picks suit buyers who want a higher MERV figure in the same size.
Starting out? See the main guide: Best Furnace Air Filters
Top picks at a glance
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Best OverallSimply 20x30x1 Air Filter9.8 View on Amazon -
9.8 View on Amazon -
Also GreatFilter King 20x30x1 Air Filter MERV9.7 View on Amazon -
Also GreatFiltrete 20x30x1 Air Filter9.6 View on Amazon -
Also GreatAerostar Air Filter 20x30x1 MERV 11 AC9.2 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. Simply 20x30x1 Air Filter | MERV 8 | 6-pack | — | — |
| 2. Amazon Basics 20x30x1 Air Filter 6-Pack | MERV 11 | 6-pack | — | — |
| 3. Filter King 20x30x1 Air Filter MERV | MERV 8 | 12-pack | — | — |
| 4. Filtrete 20x30x1 Air Filter | MERV 11 | — | — | — |
| 5. Aerostar Air Filter 20x30x1 MERV 11 AC | MERV 11 | 6-pack | — | — |
Simply 20x30x1 Air Filter
A MERV 8 pleated filter in a 6-pack, with up to 3 months of filtration and airflow arrows for easy slot insertion.
- MERV rating: MERV 8
- Pack size: 6-pack
Good for
- Buyers who want a MERV 8 filter in a 6-pack
- Owners of 20x30x1 slots who change filters every 3 months
Skip it if
- You want a MERV 11 filter
- You want a 12-pack on hand
It is a pleated MERV 8 filter in a 6-pack, with up to 3 months of filtration per filter. Airflow arrows guide insertion into a central unit or return grille. The frame is white, and the maker says it uses 100% American components, including recycled materials.
Amazon Basics 20x30x1 Air Filter 6-Pack
A MERV 11 filter in a 6-pack that captures particles as small as 3 microns, with a beverage board frame and wire mesh support.
- MERV rating: MERV 11
- Pack size: 6-pack
Good for
- Buyers who want a MERV 11 filter in a 6-pack
- Owners who change filters every 60 to 90 days
Skip it if
- You want a 12-pack on hand
- You want to go longer than 90 days between changes
It is a MERV 11 filter in a 6-pack, made with synthetic material that is electrostatically charged to attract and capture particles as small as 3 microns. The frame is beverage board with wire mesh support, and the airflow arrow points toward the furnace or blower. A 6-pack covers up to 12 months with changes every 60 to 90 days.
Filter King 20x30x1 Air Filter MERV
A MERV 8 pleated filter in a 12-pack with up to 90 days of use, for buyers who want spares on hand.
- MERV rating: MERV 8
- Pack size: 12-pack
Good for
- Buyers who want a 12-pack of MERV 8 filters
- Owners who change filters every 30 to 90 days
Skip it if
- You want a MERV 11 filter
- You want to go longer than 90 days between changes
It is a MERV 8 pleated filter in a 12-pack, with a stated life of up to 90 days. The maker recommends changing a 1 inch filter every 30 to 90 days. Installation is a slide-in replacement for a home air conditioner or heater.
Filtrete 20x30x1 Air Filter
A MERV 11 filter with a 1000 MPR figure, sold as a 2-pack with 30-, 60- or 90-day app reminders.
- MERV rating: MERV 11
Good for
- Buyers who want a MERV 11 filter with app reminders
- Owners who change filters at least once every 90 days
Skip it if
- You want a 6-pack or larger
- You want to go longer than 90 days between changes
It is a MERV 11 filter with a 1000 MPR figure, sold as a 2-pack of 3-month filters. Its 3-in-1 technology pulls in and traps particles, and the maker says it captures microparticles 0.3 to 1.0 in size. The Filtrete Smart App sets 30-, 60- or 90-day reminders, and the filter carries a limited warranty.
Aerostar Air Filter 20x30x1 MERV 11 AC
A MERV 11 filter in a 6-pack with synthetic electrostatic media and a 60 to 90 day change interval.
- MERV rating: MERV 11
- Pack size: 6-pack
Good for
- Buyers who want a MERV 11 filter in a 6-pack
- Owners who change filters every 60 to 90 days
Skip it if
- You want a 12-pack on hand
- You want to go longer than 90 days between changes
It is a MERV 11 filter in a 6-pack, comparable with MPR 1000-1200 and FPR 7. It uses 100% synthetic electrostatic media, and the maker lists low air flow resistance. Change it every 60 to 90 days, or every 30 days during peak summer and winter months.
How to choose
Match the nominal size to your slot
All five picks are nominal 20x30x1, but actual sizes differ slightly between brands, so measure your current filter's frame or slot before ordering. Amazon Basics advises picking the nominal size from your current filter's frame or measurements. Each pick is made for a furnace, air conditioner or HVAC return grille.
MERV 8 versus MERV 11
MERV is a scale for how fine a particle a filter captures, so a higher MERV figure means finer capture. In this list the Simply and Filter King filters are MERV 8, while the Amazon Basics, Filtrete and Aerostar filters are MERV 11. The Filtrete also carries a 1000 MPR figure, and the Aerostar is comparable with MPR 1000-1200 and FPR 7.
Pack size and change interval
A larger pack means fewer reorders: the Filter King comes as a 12-pack, the Simply, Amazon Basics and Aerostar as 6-packs, and the Filtrete as a 2-pack. Change intervals also differ: the Filter King every 30 to 90 days, the Amazon Basics and Aerostar every 60 to 90 days, the Filtrete at least once every 90 days, and the Simply up to 3 months per filter. During peak summer and winter months, the Aerostar interval drops to 30 days.
FAQ
What does MERV mean on an air filter?
MERV is a scale for how fine a particle a filter captures. In this list, MERV 8 covers the Simply and Filter King filters, and MERV 11 covers the Amazon Basics, Filtrete and Aerostar filters.
What change intervals do these 20x30x1 filters have?
The Filter King interval is 30 to 90 days, the Amazon Basics and Aerostar intervals are 60 to 90 days, the Filtrete interval is at least once every 90 days, and the Simply interval is up to 3 months per filter.
What is the actual size of a 20x30x1 filter?
The nominal size is 20x30x1, but actual sizes vary: the Amazon Basics measures 19.75 x 29.75 x 0.75 inches, the Filter King 19.5 x 29.5 x .75 inches, and the Filtrete 19.68 x 29.68 x 0.81 inches.
Do any of these filters give change reminders?
The Filtrete Smart App sets 30-, 60- or 90-day reminders to change the filter, and it works on iOS or Android.
