MadMax Trade Supply
Prices include the sales tax we pay at purchase (shown for Minnesota; your cart updates it for your ship-to state) and, where noted, shipping. No separate tax line. Order online; we email a secure payment link before anything ships.
A stack of plain white pleated furnace air filters standing on a utility-room floor beside a furnace.

HVAC Air Filters

Replacement furnace and air-conditioner filters listed by nominal size (width x height x depth, in inches) and MERV rating. Nominal size is the rounded size printed on the filter frame; actual size is usually slightly smaller. Check the size printed on your current filter before ordering.

Shop 36 priced items

Price includes shipping and the sales tax we pay at purchase (shown for delivery to Minnesota; your cart updates it for your ship-to state). No separate tax line at checkout. Items marked "Shipping calculated before payment link" have shipping calculated and shown in your payment link before you pay. Typical delivery is a few business days in the contiguous United States. A delivery estimate is confirmed in your payment-link email. Images are representative; tap a picture to enlarge it.

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More items (quote only)

ItemSKU (internal)Price
14x20x1 air filter, MERV 8MM-HAF-001Price coming soon — request a quoteRequest a quote
14x20x1 air filter, MERV 11MM-HAF-002Price coming soon — request a quoteRequest a quote
14x20x1 air filter, MERV 13MM-HAF-003Price coming soon — request a quoteRequest a quote
14x25x1 air filter, MERV 8MM-HAF-004Price coming soon — request a quoteRequest a quote
14x25x1 air filter, MERV 11MM-HAF-005Price coming soon — request a quoteRequest a quote
14x25x1 air filter, MERV 13MM-HAF-006Price coming soon — request a quoteRequest a quote
16x20x1 air filter, MERV 8MM-HAF-007Price coming soon — request a quoteRequest a quote
16x20x1 air filter, MERV 11MM-HAF-008Price coming soon — request a quoteRequest a quote
16x20x1 air filter, MERV 13MM-HAF-009Price coming soon — request a quoteRequest a quote
16x25x1 air filter, MERV 8MM-HAF-010Price coming soon — request a quoteRequest a quote
16x25x1 air filter, MERV 11MM-HAF-011Price coming soon — request a quoteRequest a quote
16x25x1 air filter, MERV 13MM-HAF-012Price coming soon — request a quoteRequest a quote
20x20x1 air filter, MERV 8MM-HAF-013Price coming soon — request a quoteRequest a quote
20x20x1 air filter, MERV 11MM-HAF-014Price coming soon — request a quoteRequest a quote
20x20x1 air filter, MERV 13MM-HAF-015Price coming soon — request a quoteRequest a quote
20x25x1 air filter, MERV 8MM-HAF-016Price coming soon — request a quoteRequest a quote
20x25x1 air filter, MERV 11MM-HAF-017Price coming soon — request a quoteRequest a quote
20x25x1 air filter, MERV 13MM-HAF-018Price coming soon — request a quoteRequest a quote
16x25x4 air filter, MERV 8MM-HAF-019Price coming soon — request a quoteRequest a quote
16x25x4 air filter, MERV 11MM-HAF-020Price coming soon — request a quoteRequest a quote
16x25x4 air filter, MERV 13MM-HAF-021Price coming soon — request a quoteRequest a quote
20x25x4 air filter, MERV 8MM-HAF-022Price coming soon — request a quoteRequest a quote
20x25x4 air filter, MERV 11MM-HAF-023Price coming soon — request a quoteRequest a quote
20x25x4 air filter, MERV 13MM-HAF-024Price coming soon — request a quoteRequest a quote

Attributes we list for each item: Nominal size (in), Depth (in), MERV rating, Pack size.

Buying guides

FAQ

How do I find my air filter size?

Read the size printed on the cardboard frame of your current filter, for example 16x25x1. Use that nominal size in the lookup.

Which MERV rating should I pick?

Use the rating your HVAC equipment maker or contractor recommends. Higher MERV filters capture smaller particles but can restrict airflow on some systems.

How often should I replace it?

Follow your equipment manufacturer's guidance. Many 1-inch filters are changed every 1–3 months; thicker media filters last longer.