Furnace Filters
Best 20x20x1 Furnace Filters (2026): 5 Models Side by Side
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For the best 20x20x1 furnace filters, the Filtrete leads as Best Overall: it pairs MERV 5 with MPR 300 in a 6-pack of 3-month pleated filters with a Smart App reminder. The Simply runner-up pairs MERV 8 with MPR 600 in a 6-pack, and the Amazon Basics adds MERV 11.
Starting out? See the main guide: Best Furnace Air Filters
Top picks at a glance
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Best OverallFiltrete 20x20x1 Air Filter9.8 View on Amazon -
Runner-UpSimply 20x20x1 Air Filter9.7 View on Amazon -
Also GreatAerostar Air Filter 20x20x1 MERV 8 AC9.6 View on Amazon -
Also GreatAmazon Basics 20x20x1 Air Filter 6-Pack9.5 View on Amazon -
Also GreatGeneric "20 x 20 x 1 Fiberglass Air9.2 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. Filtrete 20x20x1 Air Filter | MERV 5 | 6-pack | — | — |
| 2. Simply 20x20x1 Air Filter | MERV 8 | 6-pack | — | — |
| 3. Aerostar Air Filter 20x20x1 MERV 8 AC | MERV 8 | 6-pack | — | — |
| 4. Amazon Basics 20x20x1 Air Filter 6-Pack | MERV 11 | 6-pack | — | — |
| 5. Generic "20 x 20 x 1 Fiberglass Air | MERV 1 | 4-pack | — | — |
Filtrete 20x20x1 Air Filter
It pairs MERV 5 with MPR 300, a 6-pack of 3-month pleated filters, and a Smart App reminder.
- MERV rating: MERV 5
- Pack size: 6-pack
Good for
- Buyers who want a 20x20x1 slot with MERV 5
- Buyers who want a 6-pack for repeat changes
Skip it if
- You want a filter larger than 20x20x1
- You want a MERV figure past 5
The pleated polypropylene filters measure 19.69 x 19.69 x 0.81 actual, and the box holds 6 filters for furnace and air conditioner use. Change them at least once every 90 days, and the Smart App sets 30-, 60- or 90-day reminders. The 3-in-1 technology pulls in and traps particles while letting air flow through.
Simply 20x20x1 Air Filter
It pairs MERV 8 with MPR 600, a 6-pack, a 19.75 x 19.75 x 0.75 actual size, and an installation guide.
- MERV rating: MERV 8
- Pack size: 6-pack
Good for
- Buyers who want a 20x20x1 slot with MERV 8
- Buyers who want a 6-pack for repeat changes
Skip it if
- You want a filter larger than 20x20x1
- You want filtration past 3 months without a change
The pleated filters use a 24-point beverage board with hot-rolled steel wire mesh, and the particle size is 3.0 to 10.0 microns. The box holds 6 filters with an installation guide, and they give up to 3 months of filtration.
Aerostar Air Filter 20x20x1 MERV 8 AC
It pairs MERV 8 with MPR 600, a 6-pack, electrostatically charged pleated media, and a 19.75 x 19.75 x 0.75 actual size.
- MERV rating: MERV 8
- Pack size: 6-pack
Good for
- Buyers who want a 20x20x1 slot with MERV 8
- Buyers who want electrostatically charged pleated media
Skip it if
- You want a filter larger than 20x20x1
- You want filtration past 3 months without a change
It fits most standard residential and commercial HVAC systems with a standard 1-inch filter, and it is comparable to MPR 600 and FPR 5 filters. The heavy-duty beverage board frame has moisture-resistant backing and reinforced pleats. Replacement is every 2 to 3 months, and it captures up to 90% of airborne particles.
Amazon Basics 20x20x1 Air Filter 6-Pack
It pairs MERV 11 with a 6-pack, electrostatically charged synthetic material, and a 19.75 x 19.75 x 0.75 actual size.
- MERV rating: MERV 11
- Pack size: 6-pack
Good for
- Buyers who want a 20x20x1 slot with MERV 11
- Buyers who want a 6-pack for repeat changes
Skip it if
- You want a filter larger than 20x20x1
- You want a change interval past 90 days
The pleated filters use a beverage board frame with wire mesh support, and the synthetic material is electrostatically charged to attract particles as small as 3 microns. The box holds 6 filters, enough for up to 12 months with changes every 60 to 90 days.
Generic "20 x 20 x 1 Fiberglass Air
It pairs MERV 1 with a 4-pack of fiberglass panel filters for standard 20x20x1 slots.
- MERV rating: MERV 1
- Pack size: 4-pack
Good for
- Buyers who want a 20x20x1 slot with MERV 1
- Buyers who want a 4-pack for monthly changes
Skip it if
- You want a filter larger than 20x20x1
- You want a change interval past one month
The fiberglass panel filters fit standard 20x20x1 slots and work with a wide variety of HVAC systems. Change them monthly for peak energy efficiency. The box holds 4 filters.
How to choose
Match the nominal size first
Start with the nominal size your slot takes. All five filters are 20x20x1 nominal, with actual sizes that vary slightly: the Filtrete is 19.69 x 19.69 x 0.81, and the Simply, Aerostar and Amazon Basics are 19.75 x 19.75 x 0.75. Check the actual size against your slot before ordering, and note the Generic panel filter uses the nominal 20 x 20 x 1 size.
Understand MERV and MPR
MERV and MPR are two separate scales, so compare MERV figures with MERV figures and MPR figures with MPR figures. The Filtrete is MERV 5 with MPR 300, the Simply and Aerostar are MERV 8 with MPR 600, the Amazon Basics is MERV 11, and the Generic is MERV 1. The Filtrete, Simply, Aerostar and Amazon Basics come in 6-packs, and the Generic comes in a 4-pack.
Plan changes and upkeep
The Filtrete changes at least once every 90 days with a Smart App reminder at 30, 60 or 90 days. The Simply gives up to 3 months, the Aerostar replaces every 2 to 3 months, and the Amazon Basics changes every 60 to 90 days. The Generic changes monthly.
FAQ
What MERV figures do these filters have?
The Filtrete is MERV 5, the Simply and Aerostar are MERV 8, the Amazon Basics is MERV 11, and the Generic is MERV 1.
What size furnace filter do I need?
Check the nominal size for your slot first. The Filtrete is 19.69 x 19.69 x 0.81 actual, and the Simply, Aerostar and Amazon Basics are 19.75 x 19.75 x 0.75 actual. All five are 20x20x1 nominal.
What change intervals do these filters list?
The Filtrete changes at least once every 90 days, the Simply gives up to 3 months, the Aerostar replaces every 2 to 3 months, and the Amazon Basics changes every 60 to 90 days. The Generic changes monthly.
Which filters come in a 6-pack?
The Filtrete, Simply, Aerostar and Amazon Basics come in 6-packs, and the Generic comes in a 4-pack.
