20x30x1 air filter
A 20x30x1 filter actually measures between 19.5 x 29.5 and 19.84 x 29.84 inches depending on the brand, with thickness from 0.75 to 0.88 inches.
- Printed (nominal)
- 20" x 30" x 1"
- Actual, by brand
- 8 filters listed below
- Spread between brands
- 0.34" wide, 0.34" tall, 0.13" deep
- Face area (nominal)
- 4.17 sq ft
Actual size by brand
| Brand | Width | Height | Depth | Source |
|---|---|---|---|---|
| Filterbuy | 19.63" | 29.63" | 0.75" | [1] |
| Nordic Pure | 19.63" | 29.63" | 0.75" | [2] |
| AIRx (Discount Filters) | 19.625" | 29.625" | 0.75" | [3] |
| AprilAire A20301 | 19.5" | 29.5" | 0.75" | [4] |
| Do it Best | 19.75" | 29.75" | 0.75" | [5] |
| Filtrete Dust Reduction (MPR 300) | 19.81" | 29.81" | 0.88" | [6] |
| Filtrete Allergen Defense (MPR 1000) | 19.84" | 29.84" | 0.84" | [7] |
| Filtrete High Performance (MPR 1500) | 19.84" | 29.84" | 0.78" | [8] |
MERV options
| Brand | MERV ratings sold at this size | Source |
|---|---|---|
| Filterbuy | 8, 11, 13 | [1] |
| Nordic Pure | 7, 8, 10, 12, 13, 14, 16 | [2] |
| AIRx (Discount Filters) | 7, 8, 11, 13 | [3] |
| AprilAire | 11 | [4] |
| Filtrete Dust Reduction (MPR 300) | 5 | [6] |
| Filtrete Allergen Defense (MPR 1000) | 11 | [7] |
| Filtrete High Performance (MPR 1500) | 12 | [8] |
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 | $63.99 | $10.67 | Oct 21, 2026 [2] | |
| Discount Filters (AIRx) | 8 | 6 | $69.95 | $11.66 | Oct 21, 2026 [3] | Check price |
| Discount Filters (AIRx) | 11 | 6 | $74.95 | $12.49 | Oct 21, 2026 [3] | Check price |
Printed size vs actual size
20x30x1 is the nominal size used for ordering. No brand here cuts it to a full 20 x 30. The smallest listing is AprilAire's A20301 at 19.5 x 29.5 x 0.75 inches. Filterbuy, Nordic Pure and AIRx list 19 5/8 x 29 5/8 inches (19.63). Do it Best lists 19.75 x 29.75. Filtrete is the largest, at 19.81 x 29.81 for its MPR 300 filter and 19.84 x 29.84 for its MPR 1000 and MPR 1500 filters.
That is a spread of 0.34 inches in width and height across brands, and 0.13 inches in thickness (0.75 to 0.88). Two notes from the sources: Filterbuy's own page gives 19.63 x 29.63 in its product listing but 19 1/2 x 29 1/2 in its spec table, and Nordic Pure's MERV 16 version is listed slightly bigger, at 19.75 x 29.75, than its other ratings.
How to measure your slot
Measure the opening, or the old filter, edge to edge on both sides. If the opening is about 20 x 30 inches, any brand above will go in, and the Filtrete cut leaves the smallest gap. If the opening is tighter, under about 19.85 x 29.85, skip Filtrete and pick one of the 19.5 to 19.75 inch cuts. When your number falls between two brands, buy the smaller cut, because a filter that is too large will not go in at all.
Depth
All listings are nominal 1 inch, with real thickness from 0.75 to 0.88 inches. A 2 inch or 4 inch filter needs a deeper slot.
Questions
What is the actual size of a 20x30x1 filter?
It depends on the brand. AprilAire lists 19.5 x 29.5 x 0.75, Filterbuy, Nordic Pure and AIRx list about 19.63 x 29.63 x 0.75, Do it Best lists 19.75 x 29.75 x 0.75, and Filtrete lists 19.81 to 19.84 by 29.81 to 29.84, with thickness from 0.78 to 0.88 inches.
Which 20x30x1 brand is the largest?
Filtrete. Its MPR 1000 and MPR 1500 filters are listed at 19.84 x 29.84 inches, 0.34 inches wider and taller than AprilAire's A20301.
What MERV ratings are sold in 20x30x1?
Listings on this page range from MERV 5 (Filtrete MPR 300) to MERV 16 (Nordic Pure). Filterbuy and AIRx both sell MERV 8, 11 and 13.
Similar sizes
Not sure which you have? How to read and measure your filter.
Sources
- Filterbuy 20x30x1 air filter product page, read Oct 21, 2026
- Nordic Pure 20x30x1 air filter product page, read Oct 21, 2026
- Discount Filters 20x30x1 air filters (AIRx), read Oct 21, 2026
- AprilAire A20301 20x30x1 TriPure 1-Inch Filter, read Oct 21, 2026
- True Value, Do it Best 20 x 30 x 1 Furnace Filter, read Oct 21, 2026
- True Value, Filtrete 20 x 30 x 1 300 MPR Dust Reduction Furnace Filter, MERV 5, read Oct 21, 2026
- True Value, Filtrete 20 x 30 x 1 1000/1085 MPR Allergen Defense Furnace Filter, MERV 11, read Oct 21, 2026
- True Value, Filtrete High Performance Air Filter 1500 MPR, 20 x 30 x 1, read Oct 21, 2026