Furnace Filters
Best 20x25x1 Furnace Filter (2026): Our 5 Picks Ranked
As an Amazon Associate we earn from qualifying purchases. Specs below come from each product's Amazon listing; we do not test products in person.
The Simply 20x25x1 leads this list as a MERV 8 6-pack with pleated, electrostatically charged media and an actual size of 19.75 by 24.75 by 0.75 inches. The Filtrete runner-up steps up to MERV 11 with MPR 1000, while the Aerostar matches MERV 11 at MPR 1200 in its own 6-pack.
Starting out? See the main guide: Best Furnace Air Filters
Top picks at a glance
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Best OverallSimply 20x25x1 Air Filter9.8 View on Amazon -
Runner-UpFiltrete 20x25x1 Air Filter9.4 View on Amazon -
Also GreatFilter King 20x25x1 Air Filter MERV9.2 View on Amazon -
Also GreatAmazon Basics 20x25x1 Air Filter 6-Pack9.2 View on Amazon -
Also GreatAerostar Air Filter 20x25x1 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 20x25x1 Air Filter | MERV 8 | 6-pack | — | — |
| 2. Filtrete 20x25x1 Air Filter | MERV 11 | — | — | — |
| 3. Filter King 20x25x1 Air Filter MERV | MERV 8 | 6-pack | — | — |
| 4. Amazon Basics 20x25x1 Air Filter 6-Pack | MERV 8 | 6-pack | — | — |
| 5. Aerostar Air Filter 20x25x1 MERV 11 AC | MERV 11 | 6-pack | — | — |
Simply 20x25x1 Air Filter
A MERV 8 6-pack with pleated, electrostatically charged media, a 19.75 by 24.75 by 0.75 inch actual size and up to 3 months of filtration.
- MERV rating: MERV 8
- Pack size: 6-pack
Good for
- Buyers who want a MERV 8 6-pack for home furnaces
- Buyers who want pleated media with wire mesh support
Skip it if
- You need a MERV rating above 8
- You need a pack smaller than 6 filters
The pleated media is electrostatically charged synthetic material on a 24-point beverage board with hot-rolled steel wire mesh. The actual size is 19.75 by 24.75 by 0.75 inches, and filtration lasts up to 3 months. It slides into central units or return grilles following the airflow arrows.
Filtrete 20x25x1 Air Filter
A MERV 11 2-pack with MPR 1000, pleated 3-in-1 technology and a 90-day change interval.
- MERV rating: MERV 11
Good for
- Buyers who want MERV 11 filtration at MPR 1000
- Buyers who want a 2-pack for 3-month changes
Skip it if
- You need a MERV rating above 11
- You need more than 2 filters in the box
The 3-in-1 technology pulls in and traps particles, with a 1000 MPR and MERV 11 rating. The 2-pack covers 3-month filters, and the maker advises changing at least once every 90 days. A smart app sets 30-, 60- or 90-day reminders. It fits furnaces, air conditioners and heating systems.
Filter King 20x25x1 Air Filter MERV
A MERV 8 6-pack with pleated media, a 19.5 by 24.5 by 0.75 inch actual size and up to 90 days per filter.
- MERV rating: MERV 8
- Pack size: 6-pack
Good for
- Buyers who want a MERV 8 6-pack at a 19.5 by 24.5 inch actual size
- Buyers who change filters every 30 to 90 days
Skip it if
- You need a MERV rating above 8
- You need an actual size of 19.75 by 24.75 inches
The pleated MERV 8 filter comes in a 6-pack at an actual size of 19.5 by 24.5 by 0.75 inches. Filters last up to 90 days, and the maker recommends changing every 30 to 90 days for 1-inch filters. The pleated design captures more particles without impacting air flow. It slides in with a simple open, slide and close fit.
Amazon Basics 20x25x1 Air Filter 6-Pack
A MERV 8 6-pack with electrostatically charged synthetic material, a beverage board frame and wire mesh support.
- MERV rating: MERV 8
- Pack size: 6-pack
Good for
- Buyers who want a MERV 8 6-pack for standard furnaces
- Buyers who want replacements for up to 12 months
Skip it if
- You need a MERV rating above 8
- You need a pack smaller than 6 filters
The synthetic material is electrostatically charged to attract and capture particles as small as 3 microns. A beverage board frame with wire mesh support holds the pleated filter together. The 6-pack covers up to 12 months with changes every 60 to 90 days. Insert it with the airflow arrow pointing toward the furnace or blower.
Aerostar Air Filter 20x25x1 MERV 11 AC
A MERV 11 6-pack at MPR 1200, with pleated, electrostatically charged media that traps up to 95% of airborne particles.
- MERV rating: MERV 11
- Pack size: 6-pack
Good for
- Buyers who want MERV 11 filtration at MPR 1200
- Buyers who want a 6-pack with wire backing
Skip it if
- You need a MERV rating above 11
- You need a pack smaller than 6 filters
A beverage board frame with wire backing resists humidity and temperature changes. The actual size is 19.75 by 24.75 by 0.75 inches, and replacement runs every 2 to 3 months. It fits standard residential and commercial systems with a 1-inch slot.
How to choose
Read MERV and MPR together
MERV rates how well a filter captures particles, and MPR is a separate maker scale for the same idea. The Simply, Filter King and Amazon Basics sit at MERV 8, while the Filtrete and Aerostar sit at MERV 11. The Filtrete carries MPR 1000 and the Aerostar carries MPR 1200, so read MPR next to MERV, not instead of it. Higher MERV means finer capture, not a better fit.
Check actual size before ordering
Nominal size is not the size in the slot. The Simply, Amazon Basics and Aerostar measure 19.75 by 24.75 by 0.75 inches, while the Filter King measures 19.5 by 24.5 by 0.75 inches and the Filtrete measures 19.68 by 24.68 by 0.81 inches. Measure your current filter frame or the slot itself, then match the actual size. A filter that is too large will not slide in, and one that is too small leaves gaps.
Change intervals and pack counts
A 6-pack lasts longer between orders than a 2-pack, but only if you change on schedule. The Simply lasts up to 3 months per filter, the Filter King up to 90 days, and the Amazon Basics 6-pack covers up to 12 months at 60 to 90 day changes. The Filtrete 2-pack needs a new order sooner, with changes at least every 90 days. Match the pack to your change schedule.
FAQ
What does MERV 8 mean for a furnace filter?
MERV rates particle capture, with higher numbers capturing finer particles. The Simply, Filter King and Amazon Basics here sit at MERV 8, while the Filtrete and Aerostar sit at MERV 11.
When should I replace a 20x25x1 filter?
The Simply lasts up to 3 months, the Filter King up to 90 days, and the Amazon Basics 6-pack covers up to 12 months at 60 to 90 day changes. The Filtrete needs changing at least every 90 days.
Do all five filters fit the same slot?
All five are nominal 20x25x1, but actual sizes differ. The Simply, Amazon Basics and Aerostar measure 19.75 by 24.75 by 0.75 inches, the Filter King measures 19.5 by 24.5 by 0.75 inches, and the Filtrete measures 19.68 by 24.68 by 0.81 inches.
What comes in the box with these filters?
The Simply box holds 6 filters and an installation guide. The Filtrete box holds 2 filters, the Filter King box holds 6 filters, and the Amazon Basics and Aerostar boxes hold their 6-packs.
