12x24x2 MERV 11 Pleated Air Filter
Actual Size: 11.375x23.375x1.75"
Free Delivery 
Factory-Direct Low Prices, Made in the USA
Hassle-Free Returns & Free Exchanges
RESIDENTIAL AND/OR COMMERCIAL USE
Change Every 3 Months
Actual Size: 11.375x23.375x1.75"
Free Delivery Factory-Direct Low Prices, Made in the USAHassle-Free Returns & Free ExchangesRESIDENTIAL AND/OR COMMERCIAL USE
Change Every 3 Months
Actual Size: 11.375x23.375x1.75"
Free Delivery Factory-Direct Low Prices, Made in the USAHassle-Free Returns & Free ExchangesRESIDENTIAL AND/OR COMMERCIAL USE
Change Every 3 Months
About
- This is a list 11.75x23.75x1.75 MERV 11 air filter replacement for your furnace, air conditioner, heat pump, or HVAC system
- Actual air filter size: 11.375x23.375x1.75"
- MERV 11 synthetic media (comparable with MPR 1000/1200 and FPR 7) offers superior protection from dust, pollen, pet dander, mold, smog and more by trapping 95% of airborne particles without impacting air flow
- High-quality construction means electrostatically charged pleated filter media, reinforced wire backing for structural integrity, and a durable frame to resist heat and humidity
- Built to last 3 months. 300% longer than fiberglass models
- 100% manufactured in the United States and designed with recyclable materials
- Learn more about 11.75x23.75x1.75 Air Filters
Top-Rated Filters. American Made. Delivered Free.
At Filterbuy, we don't cut corners—we craft high-quality air filters right here in the USA and ship them to your doorstep for free. No delays, no gimmicks—just clean air, made easy. With thousands of five-star reviews and filters built for real life & every HVAC system, it's no wonder why over 4 million families trust Filterbuy.
Proudly Made In The USA
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Premium Materials That Go The Distance
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Save Up to 70% Per Filter with Packs
Things to Know About Filter Sizes
Nominal Size
- The rounded size printed on your filter or HVAC unit (e.g., 11.75x23.75x1.75).
- Usually whole numbers to make identifying and ordering easier.
- A label for compatibility—not the exact measurement.
Actual Size
- The true, trimmed dimensions of the filter (e.g., 11.375x23.375x1.75" inches).
- Filters are manufactured slightly smaller so they slide into the filter slot without forcing.
- If you don't know your nominal size, measure your filter to get the actual size, then round up to find the nominal size to search on our site.
Why the difference?
- Nominal sizes simplify shopping and standardize categories.
- Actual sizes ensure the filter fits properly inside your HVAC's filter rack.
How To Find Your Nominal Size When You Don't Know It
Measure length × width × depth with a tape measure to find the actual size.
Round up each dimension to the nearest whole number to get the nominal size. Example: 11.375x23.375x1.75" in → 11.75x23.75x1.75 nominal.
Search by nominal size on our site for the best fit.
Why Getting the Right Size Matters
- Too small? Air can bypass the filter, reducing air quality and efficiency.
- Too big? It won't fit—risking bent frames and airflow issues.
- Just right? You get maximum performance, better filtration, and cleaner air.
Free Exchange Policy
If the filter you buy doesn't fit, we'll send you a better size.
What's a MERV Rating?
MERV stands for Minimum Efficiency Reporting Value—but don't let the technical name fool you. It's just a way to rate how well an air filter traps stuff like dust, pollen, pet dander, and smoke. The higher the MERV number, the more particles it catches—and the cleaner your air will be.
| What it captures | MERV 8EssentialDust & Allergen Defense | MERV 11AdvancedPet & Allergen Defense | MERV 13PremiumPet & Allergen Defense |
|---|---|---|---|
| Comparable ratings | MPR 700 & FPR 5 | MPR 1200 & FPR 7 | MPR 1500-1900 & FPR 10 |
| Dust & Debris | Yes | Yes | Yes |
| Dust Mites | Yes | Yes | Yes |
| Pollen | Yes | Yes | Yes |
| Mold | Yes | Yes | Yes |
| Lint | Yes | Yes | Yes |
| Dander | Yes | Yes | Yes |
| Smoke & Smog | No | Yes | Yes |
| Bacteria | No | No | Yes |
| Odors | No | No | No |
| Shop MERV 8 | Shop MERV 11 | Shop MERV 13 |
What Makes Our Filters Last 90 Days? Quality, From the Inside Out
We build every Filterbuy filter to deliver reliable 90-day performance—thanks to smart design and premium materials that do the heavy lifting. Here's what makes the difference:
Pleated Design
More pleats = more surface area to capture dust and debris, keeping your air cleaner longer.
Electrostatically Charged Media
Pleats are magnetized to attract and trap microscopic particles—like pet dander, pollen, and smoke.
Synthetic Beverage Board Frame
Engineered to resist warping in extreme temperatures and high humidity.
Aluminum Dual Wire Backing
A layer of metal reinforcement keeps pleats evenly spaced and structurally sound—no sagging, even at high airflow.
Made in the USA
Assembled with care. Built to perform. Ships fast, free, and reliably from our U.S. facilities.
How to Install Your Filter in 4 Simple Steps
Turn Off Your HVAC SystemSafety first.
Remove The Old FilterLook for the airflow arrow and make note of the direction.
Slide In Your New FilterArrow should point toward the system (same direction as before).
Turn Your System Back OnAnd enjoy the fresh, clean air.
Never forget to replace your air filter again.
- Save 5% on every order
- Choose Your Delivery Schedule
- Edit, Skip, or Cancel Anytime.
Pleated Filters vs. Fiberglass—What's the Difference?
Not all air filters are created equal. Pleated filters don't just last longer—they actually clean your air better. Here's how they stack up:
Pleated Filters
Efficiency:
High (MERV 8–13) – Traps more particles
Lifespan:
90 days – Long-lasting performance
Air Quality:
Excellent – Cleaner, healthier air
Materials:
Recyclable and durable
Fiberglass Filters
Efficiency:
Low (MERV 4 or less) – Misses small stuff
Lifespan:
30 days or less – Replace often
Air Quality:
Minimal – Basic protection only
Materials:
Thin, flimsy, and not recyclable
Pleated filters are a no-brainer—more protection, less hassle, and better air for your home.
How Often Should You Change Your Filter?
Changing your filter on time keeps your HVAC system running efficiently—and helps protect your lungs from dust, allergens, and airborne irritants. Here's how often to swap it out based on your needs:
Every 90 Days
Standard ScheduleFor most homes without pets or special air quality concerns. Great for general upkeep and energy efficiency.
Every 60 Days
If You Have Pets or AllergiesShedding fur, dander, and allergy triggers can build up fast. Changing your filter every two months helps keep the air fresher and symptoms at bay.
Every 30 Days
If You Have Respiratory Concerns or Live in Smog/Wildfire ZonesFor households affected by smoke, pollution, or respiratory conditions, monthly changes ensure maximum protection.
Want to stay on track? Set a reminder—or skip the stress with auto-delivery so fresh filters show up right when you need them.
Don't Just Take Our Word For It...
Got More Questions? We've Got Answers.
Product Specifications
| Nominal Size | 11.75 x 23.75 x 1.75 inches |
| Actual Size | 11.375 x 23.375 x 1.75" inches |
| Filter Type | Pleated |
| Media | Electrostatically Charged |
| Frame | Beverage Board |
| MERV Ratings Available | 8, 11, 13 |
| Lifespan | Up to 90 Days |
| Origin | Made in USA |
Best 12x24x2 MERV 11 Furnace & HVAC Air Conditioner Filters
By Michelle Wan, Brand Manager and Air Quality Writer, Filterbuy · Technically reviewed by David Clark, Licensed HVAC Technician, Filterbuy HVAC Solutions · Published October 30, 2026 · Updated October 30, 2026
TL;DR
A 12x24x2 MERV 11 air filter is a 2-inch pleated furnace and AC filter. It's Filterbuy's Superior tier, rated Best for Allergy Sufferers, and it captures pollen, dust mite debris, mold spores, and pet dander as air moves through your HVAC system. Filterbuy cuts each one to order in its own US plants, and each lasts up to 90 days.
Key Takeaways
Filterbuy MERV 11 (Superior): Captures 95% of Airborne Particles.
Filterbuy recommends MERV 11 for allergies and asthma, and for homes with pets or pollen. MERV 8 is the standard choice for most homes, and MERV 13 is the pick for smoke.
Change it every 90 days in a typical home and every 60 days with pets or allergies.
A year of filters costs $52.36 per slot with a 12-pack, about $19 more than MERV 8.
Research modeled 10–25% of air slipping around loose-fitting filters, so a snug fit matters.
Which 12x24x2 MERV Rating Should You Choose?
Choose MERV 11 if anyone in your home has allergies or asthma, or if you have pets. MERV 8 is the standard choice for most homes, and MERV 13 is Filterbuy's pick for smoke. Filterbuy, a family-owned US manufacturer that sold its first filter in 2013, makes the 12x24x2 in all three tiers.
MPR and FPR are third-party rating systems used by other brands. Filterbuy rates its filters on the MERV scale.
Filterbuy's 3-question rule for choosing a 12x24x2 MERV rating:
Is your filter slot 2 inches deep? If it is, 12x24x2 is your size. If it's 1 inch, you need a 12x24x1.
Does anyone have allergies or asthma, or do you have pets? Choose MERV 11. If not, MERV 8 is the standard choice.
Is smoke your main concern? Choose MERV 13.
Whichever tier you pick, check your HVAC manual for the MERV ratings your system supports. It's the same fit check as confirming your size.
What Is a 12x24x2 MERV 11 Air Filter?
A 12x24x2 MERV 11 air filter is a 2-inch pleated HVAC filter for furnaces, air handlers, heat pumps, and return grilles built for 2-inch filters. MERV (Minimum Efficiency Reporting Value) is the industry's 1–16 rating scale, and higher numbers catch smaller particles. Filterbuy builds this filter to these specs:
Filterbuy uses beverage board, a moisture-resistant paperboard, for the frame. That's because 2-inch filters often sit in hot attics and damp basements, where standard cardboard warps.
How Do I Find My 12x24x2 Filter Size?
Finding your size takes a minute. Check the size printed on your old filter's frame and order by that nominal size, 12x24x2. Filterbuy's filter actually measures 11.375 x 23.375 x 1.75 inches. It's cut a little smaller on purpose, and that clearance is what lets it slide in without bending.
Label worn off? Measure the old filter's length, width, and depth, then round each up to the next whole inch. No old filter? Measure the empty slot and round to the nearest whole inch. Double-check the depth. It's the measurement Filterbuy's manufacturing team sees ordered wrong most often.
A snug fit matters with any rating. A Lawrence Berkeley National Laboratory study modeled 10% of air slipping around a filter in a loose slot, and 25% when there's a large gap.
Size not listed? Filterbuy cuts custom air filters to the eighth of an inch. If a filter doesn't fit, Filterbuy's free exchange policy covers it.
What Does a MERV 11 Air Filter Capture?
A Filterbuy MERV 11 filter captures dust, lint, pollen, dust mite debris, mold spores, and pet dander. On Filterbuy's ladder, MERV 11 (Superior) Captures 95% of Airborne Particles. Filterbuy's guide to MERV ratings explains the scale in more detail.
Is a 12x24x2 MERV 11 Filter Good for Allergies?
Yes. MERV 11 is Filterbuy's Superior tier, rated Best for Allergy Sufferers, and it's the tier Filterbuy recommends for allergies and asthma. It captures common airborne particles like pollen, dust mite debris, and mold spores. Two habits get the most from it:
Change it every 60 days during allergy season.
Run the fan longer on high-pollen days. The EPA notes that home HVAC systems typically run less than 25% of the time during heating and cooling seasons, and a filter only cleans air while the blower runs.
Questions about allergy or asthma symptoms? Talk to your doctor.
What actually hurts systems is the filter nobody remembered to change. I would rather you run MERV 11 on a real schedule than MERV 13 for eight months.
Michelle Wan, Brand Manager and Air Quality Writer, Filterbuy
Is a MERV 11 Filter Good for Homes With Pets?
Yes. MERV 11 is the tier Filterbuy recommends for homes with pets. It captures pet dander, the tiny skin flakes cats and dogs shed, along with pet hair. Pet dander is lightweight and can stay airborne for long periods, according to the American Lung Association.
Pet hair fills a filter faster, so try the white-paper check. At day 30, hold the filter against a sheet of white paper. Gray and matted? Replace it. Still light? Check again at day 60. After two checks, you'll know your home's real interval.
MERV ratings measure particles, not gases, so MERV 11 won't absorb litter-box or wet-dog smells. For odors, Filterbuy makes Odor Eliminator carbon filters.
How Long Does a 12x24x2 MERV 11 Air Filter 6-Pack Last?
A 12x24x2 MERV 11 air filter 6-pack lasts 18 months if you change filters every 90 days, or 12 months if you change them every 60. Those are the two schedules Filterbuy Auto Delivery customers choose most: every 90 days for standard homes and every 60 days for homes with pets.
*Filterbuy prices on September 29, 2026, before the 5% Auto Delivery discount. Coverage assumes one filter slot.
What a year of 12x24x2 MERV 11 filters costs (one slot):
Buying singles, every 90 days: $109.00
6-pack, every 60 days (pets or allergies): $85.62
12-pack, every 90 days: $52.36, or $49.74 with Auto Delivery
For comparison, a year of 12x24x2 MERV 8 filters costs $33.32, and MERV 13 costs $59.04, at 12-pack prices. Filterbuy Auto Delivery saves 5%, emails you three days before each shipment, and lets you change or cancel your schedule anytime.
How to Replace a 12x24x2 MERV 11 Furnace Filter
Replacing a 12x24x2 MERV 11 furnace filter takes about two minutes. Watch the airflow arrow: it points toward the blower.
Turn off your furnace or HVAC system at the thermostat.
Slide out the old filter and note which way its arrow points.
Slide in the new filter with the arrow pointing toward the air handler.
Check that it sits flat without bowing or rocking. If you had to force it, recheck your size.
Turn the system back on and write the date on the frame.
Where Can I Buy 12x24x2 MERV 11 Air Filters Near Me?
Online is usually the quickest way to get a 12x24x2 MERV 11 filter. Stores tend to stock 1-inch sizes, so 2-inch filters like this one can be hard to find on the shelf. Filterbuy is a manufacturer, not a reseller. Filters are cut, pleated, and framed to order in Filterbuy's own US plants, with fast and free 2-day delivery to most US states.
As a second-generation, family-owned company, Filterbuy has earned 85,000+ five-star reviews. Need help choosing? Filterbuy's customer care team is at (855) 345-8289.
Supporting Statistics
Three U.S. government findings behind this guide:
About 90% of our time is spent indoors. Indoor levels of some pollutants are often 2 to 5 times higher than outdoor levels. Source: U.S. EPA, Indoor Air Quality
1 in 4 U.S. adults (25.2%) has a diagnosed seasonal allergy. Source: CDC NCHS, Data Brief No. 545 (2026)
Changing a dirty filter can cut an air conditioner's energy use by 5%–15%. Sources: DOE, Home Cooling 101; DOE, Air Conditioner Maintenance
12x24x2 MERV 11 Air Filter FAQs
How Often Should I Change a 12x24x2 MERV 11 Filter?
Change it every 90 days in a typical home, every 60 days with pets or allergies, and every 30 days during wildfire smoke or renovation dust. Filterbuy's guide to how often to change your air filter covers more cases.
What's the Actual Size of a 12x24x2 Air Filter?
Filterbuy's 12x24x2 filter actually measures 11.375 x 23.375 x 1.75 inches. The 12x24x2 label is the nominal size you order by, and the slightly smaller cut is what lets the filter slide into the slot.
Can I Use a 12x24x2 Filter in a 12x24x1 Slot?
No. A 2-inch filter won't fit a 1-inch slot, so buy the depth your system takes. Filterbuy makes the same MERV 11 filter in 1-inch sizes, too.
Is a MERV 11 Filter Good for Smoke?
For smoke, Filterbuy recommends MERV 13, its Optimal tier. It comes in the same 12x24x2 size. MERV 11 is the pick for allergies, asthma, pets, and pollen.
Which MERV Rating Works With My System?
Check your HVAC manual for the MERV ratings your system supports, the same way you'd confirm your size. If the manual doesn't say, ask your HVAC technician.
Glossary
MERV (Minimum Efficiency Reporting Value): The industry's 1–16 scale for how well an air filter captures airborne particles. Higher numbers catch smaller particles.
ASHRAE: The American Society of Heating, Refrigerating and Air-Conditioning Engineers, which wrote the MERV test.
Nominal size: The rounded size printed on a filter frame and used for ordering, such as 12x24x2.
Actual size: A filter's true measured dimensions, slightly smaller than nominal so it fits the slot.
Filter bypass: Air that slips around a filter through gaps in the slot instead of passing through it.
MPR and FPR: Third-party rating systems used by other brands. They are separate from MERV.
About the author: Michelle Wan is Brand Manager and Air Quality Writer at Filterbuy. She works directly with Filterbuy's US manufacturing team and writes from how filters are built and used.
About the reviewer: David Clark is a Licensed HVAC Technician with Filterbuy HVAC Solutions who reviews Filterbuy's technical guidance for accuracy.