Furnace Filters
Best 16x20x4 Furnace Filter (2026): 5 Picks Compared
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For a 16x20x4 furnace filter, the Filter King leads this list: it is a MERV 8 filter in a 4-pack with a pleated design that lasts up to 90 days. The Filtrete and Nordic Pure step up to MERV 12, while the Aerostar 6-pack and Glasfloss 6-pack cover larger replacement runs.
Starting out? See the main guide: Best Furnace Air Filters
Top picks at a glance
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Best OverallFilter King 16x20x4 Air Filter MERV9.8 View on Amazon -
Runner-UpFiltrete 16x20x4 Air Filter9.7 View on Amazon -
Also GreatAerostar Air Filter 16x20x4 MERV 11 AC9.7 View on Amazon -
Also GreatNordic Pure 16x20x4 Pleated MERV 12 Air9.6 View on Amazon -
Also GreatGlasfloss ZL 16x20x4 MERV 10 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. Filter King 16x20x4 Air Filter MERV | MERV 8 | 4-pack | — | — |
| 2. Filtrete 16x20x4 Air Filter | MERV 12 | 2-pack | — | — |
| 3. Aerostar Air Filter 16x20x4 MERV 11 AC | MERV 11 | 6-pack | — | — |
| 4. Nordic Pure 16x20x4 Pleated MERV 12 Air | MERV 12 | 2-pack | — | — |
| 5. Glasfloss ZL 16x20x4 MERV 10 AC | MERV 10 | — | — | — |
Filter King 16x20x4 Air Filter MERV
A MERV 8 pleated filter in a 4-pack with an actual size of 15.5 x 19.5 x 3.75 inches.
- MERV rating: MERV 8
- Pack size: 4-pack
Good for
- Buyers who want a MERV 8 filter in a 4-pack
- Buyers who want a filter that lasts up to 90 days
Skip it if
- You need MERV above 8
- You need a pack larger than 4
The pleated filter slides into place with an open, slide and close fit, and the actual size measures 15.5 x 19.5 x 3.75 inches. It lasts up to 90 days before replacement, and the pleated design captures particles without impacting air flow. The paper media fits residential systems, and the filter comes as a 4-pack.
Filtrete 16x20x4 Air Filter
A MERV 12 filter with MPR 1550 in a 2-pack that lasts 12 months between changes.
- MERV rating: MERV 12
- Pack size: 2-pack
Good for
- Buyers who want MERV 12 with MPR 1550
- Buyers who want a 12-month filter life
Skip it if
- You need MERV above 12
- You need a pack larger than 2
The 3-in-1 technology pulls in and traps particles, and the filter captures 50% of small particles from the air passing through it. It lasts 12 months between changes, with a 2-pack in the box. The polypropylene media fits residential systems, and the Smart App sets 90-, 180- or 365-day reminders.
Aerostar Air Filter 16x20x4 MERV 11 AC
A MERV 11 filter with MPR 1200 in a 6-pack for a standard 4-inch filter slot.
- MERV rating: MERV 11
- Pack size: 6-pack
Good for
- Buyers who want MERV 11 with MPR 1200
- Buyers who want a 6-pack for replacements
Skip it if
- You need MERV above 11
- You need a pack larger than 6
The beverage board frame with wire backing resists humidity and temperature changes, and the pleated design gives more surface area. It fits a standard 4-inch filter slot, and replacement comes every 2 to 3 months.
Nordic Pure 16x20x4 Pleated MERV 12 Air
A MERV 12 filter in a 2-pack with electrostatically charged pleated media.
- MERV rating: MERV 12
- Pack size: 2-pack
Good for
- Buyers who want MERV 12 with MPR 1500-1900 equivalence
- Buyers who want a filter made in the USA
Skip it if
- You need MERV above 12
- You need a pack larger than 2
The electrostatically charged synthetic pleated media uses standard filtration at MERV 12, equivalent to MPR 1500-1900. The actual size measures 15.5 x 19.5 x 3.63 inches, and the filter fits residential systems. It comes as a 2-pack, and the standard filtration design suits mid-sized airborne particles and smoke.
Glasfloss ZL 16x20x4 MERV 10 AC
A MERV 10 filter in a 6-pack with a galvanized metal backing and exact size of 15-1/2 x 19-1/2 x 3-3/4 inches.
- MERV rating: MERV 10
Good for
- Buyers who want MERV 10 with MPR 800
- Buyers who want a 6-pack with a heavy-duty frame
Skip it if
- You need MERV above 10
- You need a pack larger than 6
The electrostatic filter gives MERV 10 efficiency with MERV 8 air flow, and the galvanized metal backing adds sturdiness. The exact size measures 15-1/2 x 19-1/2 x 3-3/4 inches, and the filter fits commercial and residential systems. It comes as a 6-pack, and replacement comes at least every 3 months.
How to choose
Match MERV to your needs
MERV sets how fine the filtration runs. The Filter King runs at MERV 8, the Glasfloss at MERV 10, the Aerostar at MERV 11, and the Filtrete and Nordic Pure at MERV 12. Higher MERV numbers pair with finer capture: the Aerostar traps up to 95% of airborne particles, and the Filtrete captures 50% of small particles. Pick the MERV number that fits what you want caught.
Compare pack size and change intervals
Pack size sets how many changes one purchase covers. The Filter King comes as a 4-pack, the Filtrete and Nordic Pure as 2-packs, and the Aerostar and Glasfloss as 6-packs. Change intervals differ too: the Filter King lasts up to 90 days, the Aerostar comes every 2 to 3 months, the Glasfloss at least every 3 months, and the Filtrete every 12 months.
Check actual size before ordering
Nominal size does not guarantee the exact fit. The Filter King actual size measures 15.5 x 19.5 x 3.75 inches, and the Glasfloss exact size measures 15-1/2 x 19-1/2 x 3-3/4 inches. The Nordic Pure actual size measures 15.5 x 19.5 x 3.63 inches. Measure your slot and compare it to the actual size before ordering, since a small gap changes the fit.
FAQ
Which filters are MERV 12?
The Filtrete and Nordic Pure are MERV 12, the Aerostar is MERV 11, the Glasfloss is MERV 10, and the Filter King is MERV 8.
How long do these filters last?
The Filter King lasts up to 90 days, the Aerostar comes every 2 to 3 months, the Glasfloss at least every 3 months, and the Filtrete every 12 months.
Which filters come in 6-packs?
The Aerostar and Glasfloss come as 6-packs. The Filter King comes as a 4-pack, and the Filtrete and Nordic Pure come as 2-packs.
What actual sizes do these filters have?
The Filter King measures 15.5 x 19.5 x 3.75 inches, the Glasfloss measures 15-1/2 x 19-1/2 x 3-3/4 inches, and the Nordic Pure measures 15.5 x 19.5 x 3.63 inches.
