PadMatch / Every humidifier water panel and furnace filter size
- Nominal size
- 16 x 25 x 1 in
- Actual size
- 15.5 x 24.5 x 0.75 in
- Depth class
- 1 in (flat panel)
- Order by
- nominal size (16 x 25 x 1 in)
- Typically installed on
- the return-air grille or blower-door slot of a great many gas furnaces and air handlers built for a 16 by 25 return
The true measured dimensions of a 16 x 25 x 1 in filter and how to order it.
The nominal size 16 x 25 x 1 in is the name on the frame; the actual size is 15.5 x 24.5 x 0.75 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.
The single most common flat furnace filter size. The actual panel is half an inch under nominal on each face and only three quarters of an inch thick, so it drops into a one-inch return-grille slot without binding.
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 1 in furnace filteractual 15.5 x 24.5 x 0.75 in
- MERV 8 vs 11 vs 13which rating to buy
- 20 x 25 x 1 in actual sizeactual 19.5 x 24.5 x 0.75 in
- 16 x 20 x 1 in actual sizeactual 15.5 x 19.5 x 0.75 in
- 20 x 20 x 1 in actual sizeactual 19.5 x 19.5 x 0.75 in
Sources: Atomic Filters nominal vs actual air filter size chart ยท American Standard: furnace filter sizes explained