21x26x5 air filter
The size printed on your filter frame is the nominal size. Buy the same nominal width, height and depth your filter slot was designed for. A 4-inch media cabinet needs a 4-inch filter, not a 1-inch one. How to choose a MERV rating · What size furnace filter do I need?
The size printed on the frame is the nominal size, which is what you use to order. The actual dimensions are usually slightly smaller. We do not have measured actual sizes for our 21x26x5 listings.
| Item | MERV | Nominal size | Pack | Price | Availability |
|---|---|---|---|---|---|
| Tier1 21x26x5 MERV 11 Pleated AC Furnace Air Filter 2 Pack (Actual Size: 19 11/16 x 20 11/16 x4 7/8) | 11 | 21x26x5 | 2 | $94.84 | In stock |
| Tier1 21x26x5 Merv 8 Pleated AC Furnace Air Filter 2 Pack (Actual Size: 19 11/16 x 20 11/16 x4 7/8) | 8 | 21x26x5 | 2 | $76.74 | In stock |
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Each size and MERV combination has its own page.
21x26x5 MERV 8 · 21x26x5 MERV 11
All HVAC air filters · All sizes we carry · What size furnace filter do I need?
FAQ
How do I find my filter size?
Read the size printed on the cardboard frame of your current filter, for example 16x25x1 (width x height x depth, in inches). Use that nominal size when you order.
Is 21x26x5 the actual size?
We list the nominal size as printed on the frame. We do not have measured actual dimensions for these items, and we do not guess them.
Which MERV rating should I buy?
Choose a MERV rating your furnace or air handler can handle. See our guide to HVAC filter MERV ratings. If your equipment manual lists a maximum rating, follow it.