Furnace Filters
Best Large Furnace Filters (2026): Our 5 Picks Ranked
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For large furnace filters, the Simply 16x20x1 leads as Best Overall: it pairs MERV 8 filtration with a 6-pack of pleated filters sized 15.75 by 19.75 by 0.75 inches. If you want a higher rating, the Filtrete 20x25x4 offers MERV 12 with MPR 1550, while the Demiwise and UBeesize rolls cut to fit vents of many sizes.
Starting out? See the main guide: Best Furnace Air Filters
Top picks at a glance
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Best OverallSimply 16x20x1 Air Filter9.8 View on Amazon -
Runner-UpDemiwise Air Vent Filters9.3 View on Amazon -
Also GreatFiltrete 20x25x4 Air Filter9.3 View on Amazon -
Also GreatHoneywell FC100A10299.2 View on Amazon -
Also GreatUBeesize Air Vent Filters9.2 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 16x20x1 Air Filter | MERV 8 | 6-pack | — | — |
| 2. Demiwise Air Vent Filters | MERV 8 | — | — | 1-year |
| 3. Filtrete 20x25x4 Air Filter | MERV 12 | — | — | — |
| 4. Honeywell FC100A1029 | MERV 11 | 2-pack | — | — |
| 5. UBeesize Air Vent Filters | MERV 8 | — | — | 1-year |
Simply 16x20x1 Air Filter
It pairs MERV 8 pleated filtration with a 6-pack in the 16x20x1 nominal size.
- MERV rating: MERV 8
- Pack size: 6-pack
Good for
- Buyers who want a 6-pack of 16x20x1 filters
- Buyers who want pleated filters for furnaces
Skip it if
- You need a MERV rating above 8
- You want a filter thicker than 1 inch nominal
It measures 15.75 by 19.75 by 0.75 inches actual size, with a pleated build of cardboard, paper and steel wire mesh. The pack holds 6 filters with an installation guide, and each filter lasts up to 3 months. It slides into central units or return grilles following the airflow arrows.
Demiwise Air Vent Filters
It offers MERV 8 triple-layer material in a 20 by 90 inch roll you cut to size.
- MERV rating: MERV 8
- 1-year warranty stated
Good for
- Buyers who want cut-to-fit material for vents
- Buyers who want adhesive hook tape included
Skip it if
- You need a MERV rating above 8
- You want a warranty longer than 1 year
It gives 1800 sq. inches of polyester material in a 20 by 90 inch roll, with 48 adhesive hook tapes in the box. The triple-layer electrostatic material fits floor, grille and ceiling vents after trimming, and each cut piece lasts 2 to 3 months.
Filtrete 20x25x4 Air Filter
It pairs MERV 12 and MPR 1550 ratings in a 2-pack of 20x25x4 filters.
- MERV rating: MERV 12
Good for
- Buyers who want a MERV 12 filter
- Buyers who want app reminders for changes
Skip it if
- You need a MERV rating above 12
- You want more than 2 filters per pack
It measures 19.88 by 24.63 by 4.31 inches actual size, with a pleated polypropylene build. The 2-pack covers 12 months per filter, and the Smart App sets 90-, 180- or 365-day reminders. Change the 4-inch filter at least once every 12 months.
Honeywell FC100A1029
It pairs MERV 11 pleated filtration with a 2-pack and a reminder magnet per filter.
- MERV rating: MERV 11
- Pack size: 2-pack
Good for
- Buyers who want a 16x25x4 filter
- Buyers who want a change reminder magnet
Skip it if
- You need a MERV rating above 11
- You want more than 2 filters per pack
It measures 24.88 by 15.94 by 4.38 inches actual size, with a pleated fiberglass build. Each filter ships in its own clear plastic bag, and the bundle adds a reminder magnet for each filter. The nominal size is 16x25x4.
UBeesize Air Vent Filters
It offers MERV 8 triple-layer material in a 20 by 120 inch roll you cut to size.
- MERV rating: MERV 8
- 1-year warranty stated
Good for
- Buyers who want cut-to-fit material for vents
- Buyers who want a 0.5-inch thick roll
Skip it if
- You need a MERV rating above 8
- You want a warranty longer than 1 year
It gives 2,400 sq. inches of polyester material in a 20 by 120 inch roll, with 48 adhesive hook tapes in the box. The 0.5-inch triple-layer material faces air in on the white side and out on the blue side, and pieces are replaced every 2 to 3 months.
How to choose
Nominal size against actual size
The Simply nominal 16x20x1 measures 15.75 by 19.75 by 0.75 inches, the Filtrete nominal 20x25x4 measures 19.88 by 24.63 by 4.31 inches, and the Honeywell nominal 16x25x4 measures 24.88 by 15.94 by 4.38 inches. Measure your slot and compare it with the actual size before you buy.
MERV ratings compared
MERV ratings rank filtration level, with a higher number meaning finer capture. The Simply, Demiwise and UBeesize carry MERV 8, the Honeywell carries MERV 11, and the Filtrete carries MERV 12 with MPR 1550. Pick the rating that matches your system and check your furnace manual for its limit.
Cut-to-fit rolls and packs
The Demiwise roll gives 1800 sq. inches and the UBeesize roll gives 2,400 sq. inches, both with 48 adhesive hook tapes. The Simply pack holds 6 filters, the Filtrete pack holds 2 filters, and the Honeywell pack holds 2 filters. Trim a roll to your vent size and secure it with the hook tape.
FAQ
What size filter fits a 16x20 slot?
The Simply nominal 16x20x1 measures 15.75 by 19.75 by 0.75 inches actual size, so compare that actual size with your slot before you buy.
Which filters can I cut to size?
The Demiwise 20 by 90 inch roll and the UBeesize 20 by 120 inch roll cut to fit vents, both with 48 adhesive hook tapes.
How long does each filter last?
The Simply lasts up to 3 months, the Demiwise lasts up to 2 to 3 months, the UBeesize pieces are replaced every 2 to 3 months, and the Filtrete lasts 12 months per filter.
Which filter has the highest MERV rating?
The Filtrete carries MERV 12 with MPR 1550, above the Honeywell at MERV 11 and the other three at MERV 8.
