20×25×4 air filter
Fits any system that takes a 20×25×4 filter. Actual size 19.75 × 24.75 × 3.75 inches, made to within 1/16 inch and measured before it ships. Made in the USA. Free shipping; you see your arrival date before you pay.
Grades and prices
| Grade | What it catches | Price per filter |
|---|---|---|
| Everyday (MERV 8) | Dust, lint and pollen. The right pick for most homes. | 4-pack $24.04 each, 6-pack $18.35 each, 12-pack $17.25 each |
| Allergy (MERV 11) | Adds pet dander and mold spores. For pets and allergy season. | 4-pack $33.66 each, 6-pack $25.70 each, 12-pack $24.15 each |
| Allergy + Smoke (MERV 13) | Adds smoke, smog and fine particles. For wildfire season and asthma. | 4-pack $37.27 each, 6-pack $28.45 each, 12-pack $26.74 each |
Subscribe and save 10%. Choose When you need it, timed to your local weather, air quality and household and billed per box, or Every few months, a box every 3, 6 or 12 months. Skip, change or cancel anytime.
Dimensions
- On the label
- 20 × 25 × 4 in
508 × 635 × 102 mm - Actual filter
- 19.75 × 24.75 × 3.75 in
502 × 629 × 95 mm - Face area
- 3.47 sq ft
0.32 m²
Where this size goes
In the 1,116 furnace and air handler models we've sized from manufacturer spec sheets:
- 489 furnaces list a 20×25×4 media cabinet as the thick-filter option for the same cabinet width.
Examples: Amana AMEC960302BN, Carrier 58CU0A040C17--12, Goodman GME80603BN, Heil and Tempstar N9MSE0401410A. Look up your model.
A 4" filter goes in a whole-house media cabinet, a box mounted beside the furnace or air handler that holds a thick filter instead of a thin one in a slot.
How often to change it
| Household | Everyday (MERV 8) | Allergy (MERV 11) | Allergy + Smoke (MERV 13) |
|---|---|---|---|
| A typical home | 6 months | 6 months | 5 months |
| With pets | 4 months | 4 months | 3.5 months |
| Pets and allergies, or smoke season | 3 months | 3 months | 2.5 months |
A 4" filter has far more pleat surface than a 1" filter, so it lasts much longer. Heating and cooling season, pollen and wildfire smoke shorten these; mild spring and fall weeks stretch them. More on timing.
How long a pack lasts
| Pack | Typical home | With pets | Everyday, a month |
|---|---|---|---|
| 4-pack | 2 years | 17 months | $4.01 |
| 6-pack | 3 years | 25 months | $3.06 |
| 12-pack | 6 years | 50 months | $2.88 |
On a subscription we send each box when your home needs it, so you never store more than you use.
Questions about 20×25×4 filters
Is 20×25×4 the real size?
Not quite, and that's normal. 20×25×4 is the size on the label. The filter itself measures 19.75 × 24.75 × 3.75 in (502 × 629 × 95 mm), a little smaller so it slides into the slot. We make ours to within 1/16 inch of that.
How much does a 20×25×4 filter cost?
In a 6-pack, Everyday (MERV 8) is $18.35, Allergy (MERV 11) is $25.70, Allergy + Smoke (MERV 13) is $28.45 per filter. A 12-pack costs a little less per filter, and subscribing saves another 10%. Free shipping in the US.
How often should I change a 20×25×4 filter?
About every 6 months in a typical home with Everyday or Allergy, and every 5 months with Allergy + Smoke. With pets, closer to every 4 months. Heating and cooling season, pollen and smoke fill it faster, so "When you need it" times each swap to your home's weather and household instead of the calendar.
Can I use a 20×24×4 instead?
No. Even an inch matters. A smaller filter leaves a gap that lets dusty air slip around it, and a bigger one won't slide in. Order the exact size printed on your old filter's edge. If it's a size no store carries, we make any custom size, priced like the next standard size up.
Will a 20×25×1 fit where my 20×25×4 goes?
A 1" filter is thinner, so it would slide in but leave a gap that lets air go around it. Stay with 20×25×4 for a 4" cabinet.
Is 25×20×4 the same as 20×25×4?
Yes. Manufacturers list the two face sides in either order. What matters is the airflow arrow on the frame: point it toward the furnace or air handler, away from the room.
What if it doesn't fit?
Tell us within 30 days and we'll send a new one free, and you keep the first. That's our fit guarantee.