Air Filters
Replacement air filters for furnace, AC, and HVAC systems — every nominal size, MERV 1–13, standard or built to your exact size to the 1/8″. Free U.S. shipping on orders $50+.
Find your air filter size
The size is printed on the frame of your current filter (e.g. 16x25x1). Pick yours below, or measure in 60 seconds. Don't see your size? Every dimension is available cut to 1/8″.
Residential air filters
The same filters the pros use, shipped to your door. 1″ and 2″ pleated for furnaces, heat pumps, and central AC — MERV 8 for everyday, MERV 11–13 for allergies, pets, and wildfire smoke.
Shop residential → Facilities & contractorsCommercial air filters
Pleated, box, and bag filters for RTUs, air handlers, schools, clinics, and multi-site portfolios. PO terms, tax-exempt purchasing, W-9/COI, and recurring delivery for qualified accounts.
Shop commercial →-
MERV 1-4Vendor:AAF FlandersFlanders EZ Flow Fiberglass MERV 1-4 Filter
Regular price From $59.99Sale price From $59.99 Regular priceUnit price Case of 12 $5.00/filter$0.00 -
MERV 10Vendor:AAF FlandersPREpleat LPD MERV 10 Standard Capacity
Regular price From $103.99Sale price From $103.99 Regular priceUnit price Case of 12 $8.67/filter$0.00 -
MERV 8Vendor:AAF FlandersNaturalAire Standard MERV 8
Regular price From $95.99Sale price From $95.99 Regular priceUnit price Case of 12 $8.00/filter$0.00 -
MERV 1-4Vendor:AAF FlandersFlanders Nested Glass EZ-Green Filter
Regular price From $114.99Sale price From $114.99 Regular price$0.00 -
MERV 10Vendor:AAF FlandersNaturalAire Microparticle MERV 10
Regular price From $137.99Sale price From $137.99 Regular priceUnit price Case of 12 $11.50/filter$0.00 -
MERV 10Vendor:AAF FlandersPREpleat LPD MERV 10 High Capacity
Regular price From $111.99Sale price From $111.99 Regular priceUnit price Case of 12 $9.33/filter$0.00 -
MERV 8Vendor:AAF FlandersCustom Size NaturalAire Standard MERV 8 Air Filter
Regular price $208.99Sale price $208.99 Regular price -
MERV 10Vendor:AAF FlandersCustom Size NaturalAire Microparticle MERV 10 Air Filter
Regular price $228.99Sale price $228.99 Regular price -
MERV 13Vendor:AAF FlandersPREpleat M13 MERV 13
Regular price From $195.99Sale price From $195.99 Regular priceUnit price Case of 12 $16.33/filter$0.00 -
MERV 11Vendor:AAF FlandersPREpleat M11 MERV 11 Standard Capacity
Regular price From $123.99Sale price From $123.99 Regular priceUnit price Case of 12 $10.33/filter$0.00 -
MERV 13Vendor:RTFCustom Size MERV 13 Pleated Air Filter
Regular price From $295.99Sale price From $295.99 Regular price$0.00 -
MERV 1-4Vendor:RTFPrimeShield MAX Airflow MERV 1-4 Fiberglass Panel Basic Air Filters
Regular price From $57.99Sale price From $57.99 Regular priceUnit price Case of 12 $4.83/filter$0.00 -
MERV 13Vendor:AAF FlandersNaturalAire Healthy Ultra MERV 13
Regular price From $174.99Sale price From $174.99 Regular priceUnit price Case of 12 $14.58/filter$0.00 -
Vendor:AAF FlandersPREpleat Activated Carbon Odor Control
Regular price From $152.99Sale price From $152.99 Regular priceUnit price Case of 12 $12.75/filter$0.00 -
MERV 1-4Vendor:KochDisposable Fiberglass Panel Filter
Regular price From $59.99Sale price From $59.99 Regular price$0.00 -
MERV 8Vendor:KochMulti-Pleat XL8 MERV 8 Standard Capacity
Regular price From $103.99Sale price From $103.99 Regular priceUnit price Case of 12 $8.67/filter$0.00 -
MERV 8Vendor:RTFPrimeShield Essential MERV 8 Pleated Air Filters
Regular price From $99.99Sale price From $99.99 Regular priceUnit price Case of 12 $8.33/filter$0.00 -
MERV 1-4Vendor:KochDisposable Polyester Panel Filter
Regular price From $69.99Sale price From $69.99 Regular price$0.00 -
Vendor:Smith Filter CorporationElectrostatic Aluminum Washable Permanent Filter
Regular price From $81.99Sale price From $81.99 Regular price$71.99 -
MERV 8Vendor:AAF FlandersPerfectPleat MERV 8 High Capacity
Regular price From $89.99Sale price From $89.99 Regular priceUnit price Case of 12 $7.50/filter$0.00 -
MERV 10Vendor:RTFPrimeShield Enhanced MERV 10 Pleated Air Filters
Regular price From $99.99Sale price From $99.99 Regular priceUnit price Case of 12 $8.33/filter$0.00 -
Vendor:Smith Filter Corporation
Custom Size Electrostatic Aluminum Washable Permanent Filter
Regular price From $179.99Sale price From $179.99 Regular price$71.99 -
MERV 1-4Vendor:AAF FlandersCustom Size Flanders EZ Flow Fiberglass MERV 1-4 Air Filter
Regular price $199.99Sale price $199.99 Regular price -
MERV 8Vendor:Smith Filter CorporationMech 8 Aluminum Washable Permanent Filter
Regular price From $87.99Sale price From $87.99 Regular price$77.99 -
MERV 11Vendor:RTFPrimeShield Advanced MERV 11 Pleated Air Filters
Regular price From $119.99Sale price From $119.99 Regular priceUnit price Case of 12 $10.00/filter$0.00 -
MERV 8Vendor:Smith Filter Corporation
Custom Size Mech 8 Aluminum Washable Permanent Filter
Regular price From $189.99Sale price From $189.99 Regular price$77.99 -
MERV 10Vendor:AAF FlandersCustom Size PREpleat LPD MERV 10 Air Filter
Regular price From $259.99Sale price From $259.99 Regular price$0.00 -
MPR 1000Vendor:FiltreteAllergen Defense Filter
Regular price From $14.99Sale price From $14.99 Regular price$0.00 -
MERV 8Vendor:Koch
Custom Size Multi-Pleat XL8 MERV 8 Air Filter
Regular price From $249.99Sale price From $249.99 Regular price$0.00 -
MERV 1-4Vendor:Koch
Custom Size Disposable Panel Air Filter
Regular price From $218.99Sale price From $218.99 Regular price$0.00 -
MERV 13Vendor:AAF FlandersCustom Size PREpleat M13 MERV 13 Air Filter
Regular price From $309.99Sale price From $309.99 Regular price$0.00 -
Vendor:Smith Filter CorporationThrift Aire Aluminum Washable Permanent Filter
Regular price From $77.99Sale price From $77.99 Regular price$67.99 -
MERV 13Vendor:RTFPrimeShield Elite MERV 13 Pleated Air Filters
Regular price From $187.99Sale price From $187.99 Regular priceUnit price Case of 12 $15.67/filter$0.00 -
MERV 8Vendor:AAF FlandersNaturalAire Standard MERV 8
Regular price $81.99Sale price $81.99 Regular priceUnit price Case of 6 $13.67/filter -
Vendor:Smith Filter Corporation
Custom Size Thrift Aire Aluminum Washable Permanent Filter
Regular price From $169.99Sale price From $169.99 Regular price$67.99 -
MERV 11Vendor:AAF FlandersCustom Size PREpleat M11 MERV 11 Air Filter
Regular price From $289.99Sale price From $289.99 Regular price$0.00 -
MPR 1550Vendor:FiltreteHealthy Living Deep Filter
Regular price From $19.99Sale price From $19.99 Regular price$0.00 -
MPR 700Vendor:FiltreteDust Reduction Filter
Regular price From $12.99Sale price From $12.99 Regular price$0.00 -
MPR 300 -
MPR 1500 Smart -
MPR 1900 -
MPR 1500
Choosing the right air filter
A quick, expert reference on MERV, depth, and sizing — so you order the right filter the first time.
MERV ratings in plain language
MERV (Minimum Efficiency Reporting Value) measures how well a filter captures particles. Higher MERV captures smaller particles but adds airflow resistance — match it to your system and your air-quality needs, not just the highest number.
1″, 2″, or 4″ depth?
The third number in your size (e.g. 16x25x1) is the depth. Deeper filters hold more dust and last longer at lower airflow resistance — if your system fits them.
Not a standard size? Build any dimension in 1/8″ increments with the custom filter builder.
Air Filters: frequently asked
Is a furnace filter the same as an AC filter?
Yes — in a central forced-air system, the furnace and the air conditioner share the same air handler and the same filter. A "furnace filter," "AC filter," "air conditioner filter," and "HVAC filter" are all the same product. Match the size and MERV to your system and you're set.
How often should I change my air filter?
A 1″ pleated filter typically lasts 30–90 days; homes with pets, allergies, or heavy use are on the shorter end. 2″ and 4″ filters last longer. If it looks gray and loaded, change it — a clogged filter strains the blower and drives up energy costs. More on that here.
What size filter do I need?
The nominal size is printed on the cardboard frame of your current filter (e.g. 16x25x1 = 16″ × 25″ × 1″ deep). Order that size. The actual cut size is usually about ½″ smaller on width and height — that's normal. Not sure? Our 60-second measuring guide walks through it, and any size is available cut to 1/8″.
What MERV rating should I use?
MERV 8 is the everyday default. Go MERV 11 for allergies or pets, MERV 13 for wildfire smoke or anyone with respiratory sensitivity. Higher isn't always better — very high MERV can restrict airflow on older systems, so if in doubt, MERV 8–11 is the safe range for most residential equipment.
Which way does the arrow on the filter point?
The airflow arrow printed on the filter frame points toward the blower / furnace — i.e. in the direction the air is moving, away from the return duct. Installed backwards, the filter is less effective and can restrict airflow.
Do you carry my exact size if it's not standard?
Yes. Any width and height, in 1″–6″ depths and MERV 1–13, is available built to your exact dimensions in 1/8″ increments through the custom filter builder — no more cutting standard filters down.
Can I set up recurring filter delivery?
Yes — subscribe to any filter at checkout for automatic delivery at 30, 60, 90, 180, or 365-day intervals and save 10%. For facility-scale recurring orders across multiple sites, our commercial team can set up standing orders and PO terms.
Do you supply businesses, schools, and government buyers?
Yes. We support PO ordering, net terms, tax-exempt purchasing, and W-9/COI documentation for qualified commercial, education, healthcare, and government accounts. Start with our commercial services page or request a quote.
Still not sure which filter you need?
Tell us your size and system — our filtration specialists (50+ years combined HVAC experience) will point you to the right filter.