16x25x4 air filter
Generic 16x25x4 filters measure 15.5 to 15.88 by 24.5 to 24.56 inches, but thickness runs from 3.63 to 4.31 inches. AprilAire's own 16x25x4 media is a different shape altogether.
- Printed (nominal)
- 16" x 25" x 4"
- Actual, by brand
- 6 filters listed below
- Spread between brands
- 0.38" wide, 0.06" tall, 0.69" deep
- Face area (nominal)
- 2.78 sq ft
Actual size by brand
| Brand | Width | Height | Depth | Source |
|---|---|---|---|---|
| Filterbuy | 15.5" | 24.5" | 3.63" | [1] |
| Nordic Pure | 15.5" | 24.5" | 3.63" | [2] |
| AIRx (Discount Filters) | 15.5" | 24.5" | 3.625" | [3] |
| Filtrete Allergen Defense (MPR 1000) | 15.88" | 24.56" | 4.31" | [5] |
| Filtrete Ultra Allergen (MPR 1550) | 15.88" | 24.56" | 4.31" | [6] |
| Filtrete Slim Fit (MPR 1550) | 15.88" | 24.56" | 3.7" | [7] |
MERV options
| Brand | MERV ratings sold at this size | Source |
|---|---|---|
| Filterbuy | 8, 11, 13 | [1] |
| Nordic Pure | 7, 8, 10, 12, 13, 14, 15 | [2] |
| AIRx (Discount Filters) | 8, 11, 13 | [4] |
| Filtrete Allergen Defense (MPR 1000) | 11 | [5] |
| Filtrete Ultra Allergen (MPR 1550) | 12 | [6] |
| Filtrete Slim Fit (MPR 1550) | 12 | [7] |
| AprilAire 410 (cabinet media) | 11 | [8] |
| AprilAire 413 (cabinet media) | 13 | [9] |
What MERV means: EPA, "What is a MERV rating?"
Listed prices
Prices change often. These are what each seller listed on the date shown.
| Seller | MERV | Pack | Price | Each | Checked | |
|---|---|---|---|---|---|---|
| Nordic Pure | 8 | 6 | $119.99 | $20.00 | Oct 21, 2026 [2] | |
| Discount Filters (AIRx) | 11 | 6 | $149.95 | $24.99 | Oct 21, 2026 [3] | Check price |
| Nordic Pure | 13 | 6 | $159.99 | $26.67 | Oct 21, 2026 [2] |
Printed size vs actual size
16x25x4 is a nominal size. Filterbuy, Nordic Pure and AIRx list the same face, 15.5 x 24.5 inches, at about 3 5/8 inches (3.63) thick. Filtrete's deep pleat filters are larger on the face, 15.88 x 24.56 inches, and its standard versions are 4.31 inches thick. Its Slim Fit version keeps the same face but is 3.7 inches thick.
Across these brands the face differs by 0.38 inches in width and 0.06 inches in height, but thickness differs by about 0.69 inches. On a 4 inch filter, depth is the number most likely to decide whether it fits. Filtrete rates by MPR; the MERV figures above are the ones stated on its listings.
Cabinet media is not the same part
AprilAire sells 16x25x4 media for its own whole-house air purifier cabinets, the 410 (MERV 11) and 413 (MERV 13). AprilAire lists the nominal size as 16 x 25 x 4 but the actual size as 16.52 x 29.38 x 4 inches, which is larger than the printed size and nowhere near the generic cut. If your filter sits in an AprilAire cabinet, buy by part number, not by the 16x25x4 label.
How to measure your slot
Measure the face of the opening and, most importantly, its depth. A slot that takes 4.31 inches fits any of the generic filters here. If the depth is closer to 3.6 or 3.7 inches, choose a 3.63 inch cut or the Filtrete Slim Fit. If your face measurement falls between 15.5 and 15.88, the 15.5 inch cut is the one that will go in.
Equipment that takes this size
- Aprilaire 2410 (media cabinet)
Questions
What is the actual size of a 16x25x4 filter?
Filterbuy, Nordic Pure and AIRx list 15.5 x 24.5 x about 3.63 inches. Filtrete lists 15.88 x 24.56 x 4.31 inches, or 3.7 inches thick for its Slim Fit version.
Will a generic 16x25x4 replace an AprilAire 410 or 413?
Not by size. AprilAire lists the actual size of the 410 and 413 as 16.52 x 29.38 x 4 inches, while the generic filters on this page are 15.5 to 15.88 by 24.5 to 24.56 inches.
Why does thickness matter so much at this size?
The listings here range from 3.63 to 4.31 inches deep, about a 0.69 inch difference, which is far more than the difference in width or height.
Similar sizes
Not sure which you have? How to read and measure your filter.
Sources
- Filterbuy 16x25x4 air filter product page, read Oct 21, 2026
- Nordic Pure 16x25x4 air filter product page, read Oct 21, 2026
- Discount Filters, 16x25x4 AIRx ALLERGY Air Filter MERV 11, 6-Pack, read Oct 21, 2026
- Discount Filters 16x25x4 standard filters, read Oct 21, 2026
- True Value, Filtrete 16 x 25 x 4 1000 MPR Allergen Defense Deep Pleat Furnace Filter, MERV 11, read Oct 21, 2026
- True Value, Filtrete Ultra Allergen Reduction Deep Pleat Filter, 16 x 25 x 4, read Oct 21, 2026
- True Value, Filtrete 16 x 25 x 4 1550 MPR (Slim Fit) Deep Pleat Furnace Filter, MERV 12, read Oct 21, 2026
- AprilAire 410 MERV 11 Air Filter, read Oct 21, 2026
- AprilAire 413 MERV 13 Air Filter, read Oct 21, 2026