FilterBySize Furnace and AC filter sizes, actual dimensions, MERV

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20x25x5 air filter: actual size, MERV, and price

A 20x25x5 is a five-inch-class media filter for a dedicated cabinet — not a 1-inch slot. Do not substitute a 20x25x1. Do not mix it up with 20x25x4. Buy the printed size 20x25x5. The panel is smaller than 20 by 25 by 5 inches. Honeywell F100/F200 replacements (FC100A1037) are a ~4⅜ inch cartridge that Honeywell prints as 20x25x4 and that many merchants sell as 20x25x5. Filtrete’s Air Bear-fit SKUs print about 19.56 × 24.13 × 4.75; Filtrete’s Lennox-fit SKUs print about 19.63 × 24.75 × 4.31; BestAir’s Air Bear replacement prints 19.75 × 24.25 × 4.88.

Same panel, swapped axes: 25x20x5. We treat 20x25x5 as the canonical label. Order 20x25x5.

Five-inch actual depth is not one number. Honeywell 4⅜ cartridges are often sold as 20x25x5. True Aprilaire cabinets are a different family — Aprilaire 210/213 print 20x25x4 (actual 20.6 × 26.63 × 4 on Aprilaire’s shop); Space-Gard 2200/2250 replacements are typically 20x25x6. A 4⅜ Honeywell cartridge is not an Aprilaire drop-in. Measure the old cartridge depth before you order.

Actual size by brand

These numbers are copied from manufacturer or merchant product copy, not from a competitor size chart. Thickness is part of the fit: a Honeywell F100/F200 cabinet is built around a ~4⅜ inch cartridge; a Trion Air Bear cabinet is closer to ~4¾–4⅞. Those are both sold as “20x25x5.”

Brand Nominal Published actual (in.) Source
Honeywell FC100A1037 MERV 11 (F100/F200 media cabinet; often sold as 20x25x5) 20x25x4 on Honeywell’s box; 20x25x5 at many merchants 19⅞ × 24⅞ × 4⅜ (19.875 × 24.875 × 4.375) Air Quality Honeywell Store “Exact Dimensions” for FC100A1037. Honeywell prints nominal 20 × 25 × 4
Nordic Pure Honeywell/Lennox replacement (20x25x5HM series) 20x25x5 Approximately 19.88 × 24.88 × 4.38 (19⅞ × 24⅞ × 4⅜) Nordic Pure Honeywell replacements page and Amazon B004LURI4Q title “Actual Size: 19 7/8 × 24 7/8 × 4 3/8.” JB Tools 20x25x5HM8 / HM12 / HM13 listings print the same. Nordic Pure tells buyers a Honeywell 20x25x4 with 4⅜ depth is this 20x25x5 SKU
Lennox Healthy Climate 20x25x5 (X6673 family) 20x25x5 19¾ × 24¾ × 4⅜ (19.75 × 24.75 × 4.375) Lennox Healthy Climate HCC engineering bulletin: nominal 20 × 25 × 5, actual 19-3/4 × 24-3/4 × 4-3/8
Filtrete 20x25x5 MPR 1000 / MERV 11 (Lennox-fit) 20x25x5 19.63 × 24.75 × 4.31 Amazon B0BVXDDZH7 title and “exact dimensions” 19.63 in × 24.75 in × 4.31 in. Copy says designed to fit Lennox media air cleaners; “fits systems calling for a filter thickness of 4.31″ and larger”
Filtrete 20x25x5 SlimFit MPR 1900 / MERV 13 (Lennox-fit) 20x25x5 19.63 × 24.75 × 4.31 Amazon B0F9LSFKQT title “Actual Size 19.63×24.75×4.31 in.” Copy says designed to fit Lennox brand media air cleaners
Filtrete 20x25x5 MPR 700 / MERV 8 (Air Bear-fit) 20x25x5 19.56 × 24.13 × 4.75 Amazon B0B1P15PTY title “actual size 19.56 × 24.13 × 4.75 in.” Copy says designed to fit Trion Air Bear, Bryant, Carrier, and Totaline
Filtrete 20x25x5 MPR 1550 / MERV 12 (Air Bear-fit) 20x25x5 19.56 × 24.13 × 4.75 Amazon B0130EBW1S title and “exact dimensions” 19.56 in × 24.13 in × 4.75 in. Ace Hardware NDP03-5IN-2 prints the same. Copy: fits systems calling for 4.75″ and larger
Filtrete 20x25x5 MPR 1900 / MERV 13 (Air Bear-fit) 20x25x5 19.56 × 24.13 × 4.75 Amazon B0DCGN6CHP title “Actual Size 19.56 × 24.13 × 4.75 in.” Copy says designed to fit Trion Air Bear; “fits systems calling for a filter thickness of 4.75 inches and larger”
BestAir 20x25x5 Air Bear replacement MERV 11 3-pack 20x25x5 19¾ × 24¼ × 4⅞ (19.75 × 24.25 × 4.88) Target A-79298919 product copy “Actual Size: 19 3/4 × 24 1/4 × 4 7/8.” Fits Trion Air Bear Supreme 2000 and listed Skuttle / GeneralAire / Ultravation / Braeburn cabinets
BestAir 20x25x5 Ultimate Allergen 9600 MERV 13 20x25x5 19.75 × 24.25 × 4.88 BestAir manufacturer page for Ultimate Allergen 9600: “*Actual Size: 19.75″ × 24.25″ × 4.88″”
Honeywell Home CF508D2025 MERV 10 (labeled 20x25x5) 20x25x5 19.75 × 24.25 × 4.88 Home Depot CF508D2025 product copy “MERV 10 filter actual dimensions are 19.75 × 24.25 × 4.88 (in.)”

If you currently run a Honeywell FC100A1037 (~4.38 deep) and grab a Filtrete Air Bear 20x25x5 (~4.75 deep) or a BestAir Air Bear replacement (~4.88 deep), the depth difference is about ⅜–½ inch — that is not a snugger 1-inch slide-in; it is a different cabinet fit. Filtrete’s Lennox-fit 4.31 depth is closer to Honeywell’s 4.38 than the Air Bear 4.75 is. Aprilaire 210/213 (actual 20.6 × 26.63 × 4) is not this panel. Measure the old filter. Full method: how to measure.

MERV 8 vs 11 vs 13 (facts only)

MERV is ASHRAE 52.2, as summarized by EPA. Higher MERV captures a larger share of smaller particles. It also adds resistance. EPA says to pick at least MERV 13 or as high a rating as your system fan and filter slot can accommodate, and to ask an HVAC technician if you are unsure. A 5-inch MERV 13 is not HEPA. We do not claim health outcomes.

MERV EPA average capture efficiency (particle size) Typical 20x25x5 use
8 ≥20% of 1.0–3.0 µm; ≥70% of 3.0–10.0 µm Common media-cabinet replacement when the manual does not call for higher (Nordic Pure 20x25x5HM8; Filtrete MPR 700 is labeled MERV 8)
11 ≥20% of 0.30–1.0 µm; ≥65% of 1.0–3.0 µm; ≥85% of 3.0–10.0 µm Honeywell FC100A1037 OEM rating; Filtrete MPR 1000 is commonly labeled MERV 11; BestAir Air Bear 3-pack is labeled MERV 11
13 ≥50% of 0.30–1.0 µm; ≥85% of 1.0–3.0 µm; ≥90% of 3.0–10.0 µm Higher-efficiency 5-inch-class; confirm the furnace/air handler can take the extra pressure drop

Source: U.S. EPA, “What is a MERV rating?”, last updated 14 Jan 2026. Filtrete also prints an MPR number; MPR is 3M’s scale, not MERV. Compare MERV to MERV. Nordic Pure also sells a MERV 12 20x25x5 Honeywell replacement and Filtrete sells MPR 1550 / MERV 12 Air Bear SKUs; those are in the price table, not in this EPA 8/11/13 grid.

Pack prices checked 30 Aug 2026

These are public shelf/cart prices we recorded on 30 Aug 2026. They are not live. Shipping, subscribe-and-save, and store-only deals will move them. Per-filter math is pack price ÷ count, rounded to the cent.

Listing MERV Pack Price that day Per filter Merchant
Nordic Pure 20x25x5 Honeywell/Lennox replacement (actual depth 4.38) 8 2 $47.69 $23.85 JB Tools
Nordic Pure 20x25x5 Honeywell/Lennox replacement (actual depth 4.38) 8 4 $98.99 $24.75 JB Tools
Nordic Pure 20x25x5 Honeywell/Lennox replacement (actual depth 4.38) 8 1 $32.39 $32.39 JB Tools
BestAir 20x25x5 Air Bear replacement (actual depth 4.88) 11 3 $61.99 $20.66 Target
Filtrete 20x25x5 MPR 1000 Allergen Defense (Lennox-fit; actual depth 4.31) 11 2 $49.90 $24.95 Amazon
Honeywell FC100A1037 (OEM prints 20x25x4; often sold as 20x25x5; actual depth 4.38) 11 4 $200.00 $50.00 Air Quality Honeywell Store
Honeywell FC100A1037 (OEM prints 20x25x4; often sold as 20x25x5; actual depth 4.38) 11 2 $115.00 $57.50 Air Quality Honeywell Store
Honeywell FC100A1037 (OEM prints 20x25x4; often sold as 20x25x5; actual depth 4.38) 11 1 $67.50 $67.50 Air Quality Honeywell Store
Nordic Pure 20x25x5 Honeywell/Lennox replacement (actual depth 4.38) 12 2 $48.44 $24.22 Amazon
Nordic Pure 20x25x5 Honeywell/Lennox replacement (actual depth 4.38) 12 2 $53.99 $27.00 JB Tools
Filtrete 20x25x5 MPR 1550 Ultra Allergen (Air Bear-fit; actual depth 4.75) 12 1 $32.12 $32.12 Amazon
Filtrete 20x25x5 MPR 1550 Ultra Allergen (Air Bear-fit; actual depth 4.75) 12 1 $38.99 $38.99 Ace Hardware
Nordic Pure 20x25x5 Honeywell/Lennox replacement (actual depth 4.38) 13 4 $121.49 $30.37 JB Tools
Nordic Pure 20x25x5 Honeywell/Lennox replacement (actual depth 4.38) 13 2 $73.79 $36.90 JB Tools
Nordic Pure 20x25x5 Honeywell/Lennox replacement (actual depth 4.38) 13 1 $37.79 $37.79 JB Tools
Filtrete 20x25x5 MPR 1900 (Air Bear-fit; actual depth 4.75) 13 2 $79.34 $39.67 Amazon

Observed range that day: Nordic Pure’s 4.38-inch-deep Honeywell-replacement 20x25x5 was about $23.85–$32.39/filter at MERV 8, $24.22–$27.00 at MERV 12, and $30.37–$37.79 at MERV 13. For Air Bear-depth (~4.75–4.88) packs: BestAir MERV 11 3-pack $20.66, Filtrete MERV 12 1-pack $32.12–$38.99, Filtrete MERV 13 2-pack $39.67. Filtrete’s Lennox-fit MERV 11 2-pack (actual depth 4.31) was $24.95. Honeywell FC100A1037 OEM — printed 20x25x4, same 4.38 cartridge many stores file as 20x25x5 — was $50–$67.50. Amazon Basics had no 20x25x5 SKU with a printed actual, so that brand is omitted. Target Filtrete A-92295870 printed the Air Bear actual 19.56 × 24.13 × 4.75 but the product page loaded without a public cart price, so that pack is omitted rather than guessed. Filtrete MPR 700 (B0B1P15PTY) titles print the Air Bear actual; Amazon storefront and listing prices disagreed ($53.00 vs $54.04), so that pack price is omitted. Filtrete SlimFit MERV 13 (B0F9LSFKQT) titles print 19.63 × 24.75 × 4.31; that listing was not used for a price row. Home Depot Honeywell Home CF508D2025 was Akamai-blocked, so that pack price is omitted rather than guessed. Walmart Filtrete product pages were not used for prices (prefer Target; several Walmart fetches are bot-checked on this site). Aprilaire’s own shop lists 210/213 as 20x25x4 (actual 20.6 × 26.63 × 4), not 20x25x5 — omitted from both tables. No manufacturer-published Aprilaire 20x25x5 actual was found.

Where to buy

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No ranking. Stock and price change. If the slot is an odd fraction that none of these actual sizes match, measure first — that is not a 20x25x5 SKU. A 20x25x1 or 20x25x4 is not a substitute unless the published actual depth matches the old cartridge.

Sources (accessed 30 Aug 2026)