PadMatch / Every humidifier water panel and furnace filter size
- Nominal size
- 16 x 25 x 4 in
- Actual size
- 15.375 x 24.375 x 3.625 in
- Depth class
- 4 in (media cabinet)
- Order by
- nominal size (16 x 25 x 4 in)
- Typically installed on
- media-cabinet air cleaners bolted to the furnace return (Aprilaire 1410/2410/4400, Honeywell F100)
The true measured dimensions of a 16 x 25 x 4 in filter and how to order it.
The nominal size 16 x 25 x 4 in is the name on the frame; the actual size is 15.375 x 24.375 x 3.625 in. On a flat filter each face runs about half an inch under nominal and a one-inch filter is really three quarters of an inch thick.
A four-inch deep pleated media filter for a whole-house filter cabinet, not a return grille. It seats in a dedicated media cabinet such as an Aprilaire 1410/2410 or Honeywell F100. A one-inch filter will not seal in this cabinet.
Find your model
Read the number stamped on the humidifier cabinet or printed on the old pad, then match it below. Confirm the frame size before buying a generic.
- 16 x 25 x 4 in furnace filteractual 15.375 x 24.375 x 3.625 in
- MERV 8 vs 11 vs 13which rating to buy
- 20 x 25 x 4 in actual sizeactual 19.75 x 24.25 x 3.625 in
Sources: Atomic Filters nominal vs actual air filter size chart ยท AprilAire 413 MERV 13 pleated filter for 1410/2410/3410/4400 (Home Depot)