Furnace Filters
Best 20x24x1 Furnace Filter (2026): 5 Models Side by Side
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For a furnace filter, the Filtrete leads as Best Overall: it pairs MERV 5 filtration at MPR 300 with a 6-pack and a 3-month change cycle. The Aerostar follows at MERV 8 with up to 90% particle capture, and the Simply reaches MERV 11 at MPR 1000.
Starting out? See the main guide: Best Furnace Air Filters
Top picks at a glance
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Best OverallFiltrete 16x25x1 Air Filter9.8 View on Amazon -
9.4 View on Amazon -
9.4 View on Amazon -
Also GreatFilter King 16x25x1 Air Filter MERV9.3 View on Amazon -
Also GreatSimply 16x25x1 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. Filtrete 16x25x1 Air Filter | MERV 5 | 6-pack | — | — |
| 2. Aerostar Air Filter 16x25x1 MERV 8 AC | MERV 8 | 4-pack | — | — |
| 3. Flanders Disposable Air Filter E-Z Flow II | MERV 4 | 12-pack | — | — |
| 4. Filter King 16x25x1 Air Filter MERV | MERV 8 | 6-pack | — | — |
| 5. Simply 16x25x1 Air Filter | MERV 11 | — | — | — |
Filtrete 16x25x1 Air Filter
Its MERV 5 rating at MPR 300 pairs with a 6-pack and 3-in-1 technology for dust and lint.
- MERV rating: MERV 5
- Pack size: 6-pack
Good for
- Buyers who want a 6-pack of MERV 5 filters
- Buyers who want app change reminders
Skip it if
- You want a MERV rating above 5
- You want fewer than 6 filters per pack
The pleated filter measures 15.69 by 24.69 by 0.81 inches actual, against a 16x25x1 nominal size. Change it 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 from air passing through.
Aerostar Air Filter 16x25x1 MERV 8 AC
Its MERV 8 rating at MPR 600 pairs with a 4-pack and up to 90% particle capture.
- MERV rating: MERV 8
- Pack size: 4-pack
Good for
- Buyers who want MERV 8 filtration
- Buyers who want up to 90% particle capture
Skip it if
- You want a MERV rating above 8
- You want more than 4 filters per pack
The electrostatically charged pleated media traps up to 90% of airborne particles while allowing smooth airflow. Its actual size is 15.75 by 24.75 by 0.75 inches, and the heavy-duty frame with moisture-resistant backing lasts up to 3 months.
Flanders Disposable Air Filter E-Z Flow II
Its MERV 4 panel design pairs with a 12-pack for regular changes.
- MERV rating: MERV 4
- Pack size: 12-pack
Good for
- Buyers who want a 12-pack for bulk value
- Buyers who want a simple panel filter
Skip it if
- You want a MERV rating above 4
- You want fewer than 12 filters per pack
The glass panel filter captures dust, lint and airborne particles for furnaces and air conditioners. It fits most standard residential systems, and the 12-pack makes regular changes easy. Installation is a simple slide-in replacement.
Filter King 16x25x1 Air Filter MERV
Its MERV 8 pleated design pairs with a 6-pack and up to 90 days of use.
- MERV rating: MERV 8
- Pack size: 6-pack
Good for
- Buyers who want MERV 8 filtration
- Buyers who want slide-in replacement filters
Skip it if
- You want a MERV rating above 8
- You want more than 6 filters per pack
The pleated filter measures 15.5 by 24.5 by 0.75 inches actual, against a 16x25x1 nominal size. It lasts up to 90 days, with changes recommended every 30 to 90 days for 1 inch filters. The pleated design captures more particles without impacting airflow.
Simply 16x25x1 Air Filter
Its MERV 11 rating at MPR 1000 pairs with a 6-pack and 95% particle capture.
- MERV rating: MERV 11
Good for
- Buyers who want MERV 11 filtration
- Buyers who want 95% particle capture
Skip it if
- You want a MERV rating above 11
- You want more than 6 filters per pack
The pleated filter measures 15.75 by 24.75 by 0.75 inches actual, against a 16x25x1 nominal size. It lasts up to 3 months, and the higher pleat count supports airflow and efficiency.
How to choose
MERV ratings compared
MERV rates how finely a filter captures particles, with higher numbers catching smaller ones. Here the Flanders sits at MERV 4, the Filtrete at MERV 5, the Aerostar and Filter King at MERV 8, and the Simply at MERV 11. Match the rating to your system: higher ratings catch more, so check that your system handles the rating you pick.
Nominal size and actual size
All five filters carry a 16x25x1 nominal size, with actual sizes of 15.69 by 24.69 by 0.81 inches for the Filtrete, 15.75 by 24.75 by 0.75 for the Aerostar and Simply, and 15.5 by 24.5 by 0.75 for the Filter King. Check the actual size against your filter slot before ordering.
Pack size and change cycle
Pack size sets how many changes one box covers. The Flanders comes as a 12-pack, the Filtrete, Filter King and Simply as 6-packs, and the Aerostar as a 4-pack. Change cycles run up to 3 months on the Filtrete, Aerostar and Simply, and up to 90 days on the Filter King. Swap on schedule to keep airflow steady.
FAQ
What MERV rating does each filter have?
The Flanders is MERV 4, the Filtrete is MERV 5, the Aerostar and Filter King are MERV 8, and the Simply is MERV 11.
What are the actual sizes?
The Filtrete measures 15.69 by 24.69 by 0.81 inches, the Aerostar and Simply measure 15.75 by 24.75 by 0.75, and the Filter King measures 15.5 by 24.5 by 0.75.
When should I change the filter?
Change the Filtrete at least once every 90 days, and the Aerostar and Simply last up to 3 months, and the Filter King lasts up to 90 days.
Which filter captures the most particles?
The Simply carries the highest rating here at MERV 11 and MPR 1000, while the Aerostar and Filter King carry MERV 8.
