| Factor | 1-inch | 4-inch |
|---|---|---|
| Cabinet requirement | Standard narrow slot | Dedicated media cabinet |
| Surface area | Lower | Often much higher |
| Typical service interval | Shorter | Often longer |
Do not force a thicker filter into the slot
The third number in the nominal size indicates thickness. A 20x25x4 filter does not fit a 20x25x1 slot.
Thicker filters can offer more media area
More surface area may allow longer service life and lower pressure drop at comparable filtration levels, but product design varies.
Follow cabinet labeling
Use the exact dimensions and compatible models listed for your filter cabinet.
Not sure which filter fits your home?
Use the FilterMatch Finder for a practical starting recommendation based on your filter size and household needs.
Use the FilterMatch Finder