Size page
14x25x1 air filter: actual size and MERV
A 14x25x1 is a narrower one-inch furnace-slot size. Order 14x25x1.
Actual size by brand
| Brand | Published actual (in.) | Source |
|---|---|---|
| Honeywell 1-inch (MERV 8 and MERV 13 12-packs) | 13.75 × 24.75 × 0.75 | Honeywell Store product specs |
| Filtrete 14x25x1 MPR 2200 / MERV 13 6-pack | 13.81 × 24.81 × 0.78 | Amazon B07FNW9VZ9 “exact dimensions” |
Those two cuts differ by about 1/16 inch on the short side. If a Honeywell 13.75-inch filter rattled in the rack, a Filtrete 13.81 may sit better, and the reverse if the slot is tight.
MERV 8 / 11 / 13
MERV does not change the nominal size. EPA’s table (ASHRAE 52.2):
| MERV | EPA average capture efficiency |
|---|---|
| 8 | ≥20% of 1.0–3.0 µm; ≥70% of 3.0–10.0 µm |
| 11 | ≥20% of 0.30–1.0 µm; ≥65% of 1.0–3.0 µm; ≥85% of 3.0–10.0 µm |
| 13 | ≥50% of 0.30–1.0 µm; ≥85% of 1.0–3.0 µm; ≥90% of 3.0–10.0 µm |
EPA: if you upgrade, use at least MERV 13 or as high as the system fan and slot can take. Check the HVAC manual before MERV 13 in a 1-inch slot. MERV 13 is not HEPA. No health claims.
How to measure See the 16x25x1 page for a full buy table
Sources (accessed 30 Aug 2026). EPA: What is a MERV rating?. Brand actual sizes: Honeywell Store product specs and Amazon product titles/“actual size” fields cited on this page.