The most common furnace filter sizes are 20x20x1, 16x25x1, 16x20x1, and 20x25x1, which cover roughly 60 to 70 percent of homes. Your exact size is printed on the cardboard frame of your current filter. For MERV: pick MERV 8 for basic dust and pollen, MERV 11 if you have pets or mild allergies, and MERV 13 for severe allergies, asthma, or wildfire smoke. MERV 13 uses denser media, so confirm your HVAC system supports it before installing.
Our top overall pick is the Filtrete MPR 1000 Micro Allergen (~$50/6-pack), a MERV 11 that covers pets, mild allergies, and everyday dust in most homes.
Check Price on Amazon →Check the side of your current filter. The size is printed on the cardboard frame.
Standard 1-inch filters
Deep pleated 4-5 inch filters
The Filtrete MPR 1000 Micro Allergen (~$50 for a 6-pack) is the best air filter for homes with pets.
The Filtrete MPR 1500 Allergen, Bacteria & Virus (~$60 for a 6-pack) is the best air filter for allergy sufferers.
The Filtrete MPR 1900 Ultimate Allergen (~$70 for a 4-pack) is the best air filter for smoke.
The Filtrete MPR 1500 Allergen, Bacteria & Virus (~$60 for a 6-pack) is the best air filter for asthma sufferers.
The Aerostar Pleated MERV 8 (~$25 for a 6-pack) is the best budget air filter.
The Filtrete MPR 600 Clean Living (~$35 for a 6-pack) is the best air filter for household dust.
The Filtrete 4-inch MPR 1550 Allergen Defense (~$30 per filter) is the best deep pleated air filter.
The Filtrete MPR 1000 Micro Allergen (~$50 for a 6-pack) is the best starting point for homes with a new baby.
The Filtrete MPR 1200 Odor Reduction (~$55 for a 6-pack) is the best air filter for household odors.
The Aerostar Pleated MERV 8 (~$25 for a 6-pack) is the safest air filter for older HVAC systems.
Reference guides and cost calculators for air filter buyers.
MERV 11 minimum for seasonal allergies, MERV 13 for severe. Prep guides for spring pollen and fall ragweed.
The EPA recommends MERV 13 or higher for wildfire smoke. What to do before, during, and after fire season.
Find your air filter size in 3 steps. Common sizes table, nominal vs actual explained, and measuring tips.
Nordic Pure MERV 12 is the better deal for most homes.
MERV 11 is the right choice for most homes.
If you have pets or any kind of allergies, upgrading from MERV 8 to MERV 11 is worth it.
If your HVAC system has a 4-inch filter cabinet, use 4-inch filters.
What air filter should I buy if I just need basic protection?
The Aerostar Pleated MERV 8 (~$25 for a 6-pack) is the best budget air filter for basic home protection. It's MERV 8, which catches dust, pollen, lint, and carpet fibers. Made in the USA and available in over 50 sizes. If you want a name brand, the Filtrete MPR 600 Clean Living (~$35 for a 6-pack) uses 3M's electrostatic media for the same MERV 8 performance. Both are safe for any HVAC system, including older units. Replace every 90 days.
What's the best air filter if I have dogs or cats?
The Filtrete MPR 1000 Micro Allergen (~$50 for a 6-pack) is the best air filter for pet owners. It's MERV 11, which captures pet dander, fur, and dust mites that basic MERV 8 filters miss. 3M's electrostatic technology actively attracts airborne pet particles. For a lower-cost alternative, the Nordic Pure MERV 12 (~$40 for a 6-pack) actually delivers MERV 12 performance at a MERV 11 price. With pets, replace every 30 to 60 days instead of the standard 90 because pet hair clogs filters faster.
What air filter do I need for seasonal allergies?
The Filtrete MPR 1500 Allergen, Bacteria & Virus (~$60 for a 6-pack) is the top pick for allergy sufferers. Rated MERV 12 by industry standards, it captures pollen, mold spores, dust mites, and fine particles that trigger allergic reactions. It's Bob Vila's number one overall pick and a Consumer Reports top performer. For severe allergies or asthma, the Nordic Pure MERV 13 (~$50 for a 6-pack) offers MERV 13 filtration at a lower price, catching particles down to 0.3 microns including some bacteria.
What air filter should I get for wildfire smoke?
The Filtrete MPR 1900 Ultimate Allergen (~$70 for a 4-pack) is the strongest 1-inch filter for wildfire smoke. It's MERV 13 with the highest smoke particle capture rate in Filtrete's lineup. The EPA recommends MERV 13 or higher for wildfire smoke filtration. For smoke plus odor control, the Nordic Pure MERV 13 + Carbon (~$55 for a 6-pack) adds activated carbon to neutralize smoke smell while maintaining MERV 13 particle capture. During wildfire season, replace filters every 30 to 45 days.
Should I get a 4-inch or 1-inch air filter?
If your HVAC system has a 4 or 5-inch filter cabinet (common with Honeywell, Aprilaire, Lennox, and Carrier systems), always use the deep-pleated size it was designed for. Deep filters last 6 to 12 months instead of 60 to 90 days and hold far more dust. The Filtrete 4-inch MPR 1550 (~$30 per filter) is the best deep-pleated pick, with very good dust and smoke removal per Consumer Reports. The Aprilaire 213 MERV 13 (~$40 per filter) is the premium choice. You cannot use a 4-inch filter in a standard 1-inch slot.
What's the best air filter for most homes?
The Filtrete MPR 1000 Micro Allergen (~$50 for a 6-pack) is the best air filter for most homes. It's MERV 11, which captures dust, pollen, pet dander, mold spores, and dust mites. 3M's best-selling mid-tier filter, it covers the widest range of household needs without restricting airflow. Compatible with virtually all residential HVAC systems. If you're on a tighter budget, the Nordic Pure MERV 12 (~$40 for a 6-pack) delivers slightly higher MERV performance for $10 less per pack. Replace every 60 to 90 days.
MERV 8 catches dust, pollen, lint, and carpet fibers (particles 3 microns and larger). The lowest-cost quality pleated filter and the safest choice for any HVAC system, including older units. Replace every 90 days.
Cheapest quality pleated filter on Amazon. Made in USA. Available in 50+ sizes.
3M's entry-level pleated filter. Electrostatic media for enhanced dust capture.
★4.7·514 ratings
Strong mid-price value. Electrostatically charged with a moisture-resistant frame.
MERV 11 captures pet dander, dust mites, mold spores, and fine pollen (particles 1 to 3 microns). The right choice for most homes with pets or seasonal allergies. Compatible with virtually all residential HVAC systems. Replace every 60 to 90 days.
★4.8·57,181 ratings
3M's most popular mid-tier. Best overall pick for most homes with pets or mild allergies.
★4.7·3,603 ratings
MERV 12 at a MERV 11 price. Hypoallergenic, resists mold and mildew.
Same allergen filtration as MPR 1000 plus activated carbon for odor elimination.
MERV 13 filters particles down to 0.3 microns, catching smoke, bacteria, and virus carriers. The EPA recommends MERV 13 or higher for wildfire smoke and allergen management. Check your HVAC manual before installing. Replace every 60 to 90 days.
Bob Vila's #1 overall. Consumer Reports top performer. The gold standard for premium filtration.
★4.8
Highest-rated 1-inch Filtrete. Strongest smoke and fine particle capture available.
★4.6·25,195 ratings
MERV 13 performance at a lower price than Filtrete equivalents. Best value premium filter.
★4.5·46 ratings
MERV 13 particle capture plus activated carbon for smoke and odor removal.
Deep pleated filters last 6 to 12 months and hold far more debris than standard 1-inch filters. Requires a compatible 4 or 5-inch filter cabinet (common with Honeywell, Aprilaire, Lennox, and Carrier systems). You cannot use a deep filter in a standard 1-inch slot. See the full deep-pleated and box filter guide.
Lasts 12 months. Deep pleats hold 20x more than 1-inch filters. Budget deep-pleated pick.
★4.7·1,852 ratings
Deep pleated MERV 11 with 3M electrostatic technology. Replace once every 6-12 months.
★4.6
Consumer Reports: very good dust/smoke removal, nearly unrestricted airflow. Best deep-pleated pick.
★4.8
Consumer Reports: excellent at all fan speeds. Premium deep-pleated pick for Aprilaire cabinets.
★4.4·1,850 ratings
Value deep-pleated option with MERV 12 performance and moisture-resistant frame.
| Situation | You Need | Why |
|---|---|---|
| No pets, no allergies, just basic | MERV 8 | Catches dust and pollen. Lowest cost. Safe for any system. |
| Pets (cats, dogs) | MERV 11 | Traps pet dander and fur that MERV 8 misses. |
| Mild allergies (seasonal) | MERV 11 | Captures mold spores, dust mites, fine pollen. |
| Severe allergies or asthma | MERV 13 | Filters particles down to 0.3 microns including bacteria. |
| Smoker in the home | MERV 13 | Catches smoke particles and neutralizes odor (with carbon). |
| Wildfire smoke area | MERV 13 | EPA recommends MERV 13+ for wildfire smoke filtration. |
| New baby in the home | MERV 11-13 | Removes fine particles for sensitive developing lungs. |
| Older HVAC system (15+ years) | MERV 8 | Higher MERV can restrict airflow and strain older systems. Check manual. |
| MERV | Catches | Misses | Best For |
|---|---|---|---|
| MERV 8 | Dust, pollen, lint, carpet fibers (3+ microns) | Pet dander, mold spores, fine dust | Budget homes, older HVAC, renters |
| MERV 11 | All of MERV 8 + pet dander, dust mites, mold spores (1–3 microns) | Smoke, bacteria, virus carriers | Most homes with pets or mild allergies |
| MERV 13 | All of MERV 11 + smoke, bacteria, some virus carriers (0.3–1 microns) | Requires compatible HVAC | Allergies, asthma, smoke, new babies |
Filtrete prints MPR and Home Depot prints FPR instead of MERV. These are the rough equivalents, so you can match any brand to the filtration level you actually need.
| MERV (Standard) | Filtrete MPR | Home Depot FPR | Best For |
|---|---|---|---|
| MERV 8 | MPR 600 | FPR 5 | Basic dust and pollen |
| MERV 11 | MPR 1000-1200 | FPR 7 | Pets, mild allergies |
| MERV 12 | MPR 1500 | FPR 9 | Allergies, fine dust |
| MERV 13 | MPR 1900 | FPR 10 | Asthma, smoke, wildfire |
Need help converting a specific rating? Use the MERV / MPR / FPR converter.
A new filter does more when the rest of your system supports it. These accessories help your filter perform: seal duct leaks, watch your air quality, and keep airflow efficient.
★4.7·1,838 ratings·~$159
Measures CO2, temperature, and humidity so you can see when your filter and ventilation are keeping up. Tells you when air actually needs attention.
★4.4·22,782 ratings·~$87
Schedules your HVAC runtime so the system cycles efficiently. Pairs with filter changes to cut energy use and keep airflow steady.
★4.5·5,999 ratings·~$27
Seal off vents in unused rooms to direct conditioned air where you spend time. Strong magnets, easy to reposition seasonally.
★4.4·2,712 ratings·~$54
Installs in the ductwork to reduce mold and microbes on the coil and in the air handler, working alongside your filter rather than replacing it.
★4.7·8,100 ratings·~$14
Seals duct seams and the filter slot so unfiltered air does not bypass the filter. A cheap fix that makes any MERV upgrade actually work.
Accessories are complementary HVAC products, not air filters. Prices are approximate and may vary.
Most homes do best with MERV 8 to MERV 13. MERV 8 for basic protection, MERV 11 if you have pets or mild allergies, MERV 13 for severe allergies, asthma, or smoke. Don't go higher than your HVAC system can handle. Check your manual for the max MERV rating your system supports.
Check the side of your current filter. The size is printed on the cardboard frame (e.g., 20x25x1). If it's faded, measure your filter slot: length x width x depth in inches, then round up to the nearest whole number. That rounded number is your "nominal size," which is what you order.
The most common residential filter sizes are 20x20x1, 16x25x1, 16x20x1, and 20x25x1. The "1" is the standard 1-inch depth that fits most HVAC systems. These four sizes cover roughly 60 to 70 percent of homes.
Standard 1-inch filters: every 60 to 90 days. Homes with pets, allergies, or heavy dust: every 30 to 45 days. Deep pleated 4 to 5 inch filters: every 6 to 12 months. A dirty filter makes your HVAC work harder, raises energy bills, and worsens air quality.
MERV 8 catches particles 3 microns and larger (dust, pollen, lint). MERV 13 catches particles down to 0.3 microns (smoke, bacteria, virus carriers). Higher MERV means better filtration but more airflow restriction. MERV 13 is the highest rating recommended for residential use.
No. Higher MERV means denser filter media, which restricts airflow. If your HVAC system can't handle it, you'll strain the blower motor, increase energy costs, and potentially damage the system. Most residential systems handle MERV 8 through 13 fine. Check your manual for the max MERV rating.
MERV 11 minimum for seasonal allergies (pollen, dust mites, mold spores). MERV 13 for severe allergies or asthma, as it captures finer particles including some bacteria. The EPA recommends MERV 13 or higher for managing airborne allergens.
MERV 11 captures pet dander, fur, and dust mites that MERV 8 misses. If you have multiple pets or family members with pet allergies, step up to MERV 13. Replace filters every 30 to 60 days with pets because they clog faster.
MERV 13 minimum. The EPA specifically recommends MERV 13 or higher for filtering wildfire smoke particles. The Filtrete MPR 1900 (MERV 13) with carbon is a strong choice for combined smoke particle and odor removal.
MERV (Minimum Efficiency Reporting Value) is the industry standard, rated 1 to 16. MPR (Microparticle Performance Rating) is 3M/Filtrete's proprietary scale, rated 300 to 2800. FPR (Filter Performance Rating) is Home Depot's scale, rated 4 to 10. Rough equivalents: MERV 8 is about MPR 600 / FPR 5. MERV 11 is about MPR 1000 / FPR 7. MERV 13 is about MPR 1500 to 1900 / FPR 10.
Nominal size is the rounded number printed on the filter label (e.g., 20x25x1). Actual size is the exact measurement (e.g., 19.5 x 24.5 x 0.75 inches). Always order by nominal size. Filters are designed to be slightly smaller than stated for easy installation into your filter slot.
Yes, for standard 1-inch and 2-inch filters. Size and MERV matter, not brand. A 20x25x1 MERV 11 from any manufacturer fits any system with a 20x25x1 slot. For 4 to 5 inch deep-pleated filters, check that the actual dimensions match your specific filter cabinet, as they vary more between brands.
Get MERV 11 if you have pets or mild seasonal allergies. It captures pet dander, dust mites, mold spores, and fine pollen (1 to 3 microns) and runs on virtually any residential HVAC system without straining airflow. Step up to MERV 13 only for severe allergies, asthma, smokers in the home, or wildfire smoke, since it catches finer particles down to 0.3 microns including smoke and bacteria. MERV 13 uses denser media, so confirm your system supports it before installing. For most homes, MERV 11 is the better balance of filtration and airflow.
MPR (Microparticle Performance Rating) is 3M Filtrete's own scale, running 300 to 2800. Match it to your situation: MPR 600 for basic dust and pollen (about MERV 8), MPR 1000 to 1200 for pets and mild allergies (about MERV 11), and MPR 1500 to 1900 for severe allergies, asthma, or smoke (about MERV 12 to 13). A higher MPR means denser media and more airflow restriction, so do not jump to the top of the scale unless your situation and HVAC system call for it.
No. MERV is the independent industry standard (rated 1 to 16). Filtrete is a 3M brand of filters that uses its own MPR scale instead of printing a MERV number. So the choice is not MERV versus Filtrete, it is which MERV equivalent of a Filtrete filter you need. A Filtrete MPR 1000 is roughly MERV 11; an MPR 1900 is roughly MERV 13. Any brand at the same MERV equivalent and size filters comparably, so compare by MERV or MPR equivalent and price, not by brand name alone.