PadMatch / Every humidifier water panel and furnace filter size
- Nominal size
- 14 x 25 x 1 in
- Actual size
- 13.5 x 24.5 x 0.75 in
- Depth class
- 1 in (flat panel)
- Typically installed on
- narrow return-air grilles and slim blower compartments
- Sold in MERV
- sold flat-panel in MERV 8, 11 and 13
Nominal versus actual dimensions for the 14 x 25 x 1 in furnace and HVAC air filter.
A 14 x 25 x 1 in furnace filter has an actual size of 13.5 x 24.5 x 0.75 in. The label is the nominal size, rounded up so the filter is easy to name; the panel is cut undersize so it slides into the slot without binding.
The narrow flat size, actual 13.5 by 24.5 by 0.75 inches. It shares the 24.5-inch height of a 16 by 25 but is two inches narrower, so a 16 by 25 will not seat in a 14 by 25 slot.
Order by the nominal size printed on the old filter frame, not by measuring the slot, because every brand runs to the same nominal-to-actual convention.
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.
- 14 x 25 x 1 in actual sizenominal vs actual dimensions
- 16 x 25 x 1 in furnace filteractual 15.5 x 24.5 x 0.75 in
- 20 x 25 x 1 in furnace filteractual 19.5 x 24.5 x 0.75 in
- MERV 8 vs 11 vs 13 for a furnace filterwhich rating to buy
Sources: Atomic Filters nominal vs actual air filter size chart ยท Filterbuy air filter sizes chart