20×24×1 air filter
Fits any system that takes a 20×24×1 filter. Actual size 19.75 × 23.75 × 0.75 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 $9.68 each, 6-pack $7.39 each, 12-pack $6.94 each |
| Allergy (MERV 11) | Adds pet dander and mold spores. For pets and allergy season. | 4-pack $13.55 each, 6-pack $10.34 each, 12-pack $9.72 each |
| Allergy + Smoke (MERV 13) | Adds smoke, smog and fine particles. For wildfire season and asthma. | 4-pack $15.00 each, 6-pack $11.45 each, 12-pack $10.76 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 × 24 × 1 in
508 × 610 × 25 mm - Actual filter
- 19.75 × 23.75 × 0.75 in
502 × 603 × 19 mm - Face area
- 3.33 sq ft
0.31 m²
Where this size goes
In the 1,116 furnace and air handler models we've sized from manufacturer spec sheets:
- 2 furnaces take a 20×24×1 in the filter slot beside or under the blower (Rheem).
- 39 air handlers take a 20×24×1 in the unit or its filter stand (Carrier, Goodman, Lennox, Mitsubishi, Payne and others).
Examples: Rheem R98MV0855A21UPSGA, Carrier FE5BNBD60L00, Goodman AMVT48DP14, Lennox CBA38MV-042. Look up your model.
How often to change it
| Household | Everyday (MERV 8) | Allergy (MERV 11) | Allergy + Smoke (MERV 13) |
|---|---|---|---|
| A typical home | 3 months | 3 months | 2.5 months |
| With pets | 2 months | 2 months | 7 weeks |
| Pets and allergies, or smoke season | 6 weeks | 6 weeks | 5 weeks |
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 | 11 months | 7 months | $3.52 |
| 6-pack | 17 months | 11 months | $2.61 |
| 12-pack | 33 months | 22 months | $2.52 |
On a subscription we send each box when your home needs it, so you never store more than you use.
Questions about 20×24×1 filters
Is 20×24×1 the real size?
Not quite, and that's normal. 20×24×1 is the size on the label. The filter itself measures 19.75 × 23.75 × 0.75 in (502 × 603 × 19 mm), a little smaller so it slides into the slot. We make ours to within 1/16 inch of that.
How much does a 20×24×1 filter cost?
In a 6-pack, Everyday (MERV 8) is $7.39, Allergy (MERV 11) is $10.34, Allergy + Smoke (MERV 13) is $11.45 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 20×24×1 filter?
About every 3 months in a typical home with Everyday or Allergy, and every 2.5 months with Allergy + Smoke. With pets, closer to every 2 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 an 18×24×1 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 20×24×2 fit where my 20×24×1 goes?
Only if the slot is 2 inches deep. A 2" filter needs a rack or grille built 2 inches deep, so it won't fit a 1" slot. If your slot is 1", stay with 20×24×1.
Is 24×20×1 the same as 20×24×1?
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.